Old GA Citizen's Arrest Statute

Here are the two sentences that the jury instructions depended on:

A private person may arrest an offender if the offense is committed in his presence or within his immediate knowledge. If the offense is a felony and the offender is escaping or attempting to escape, a private person may arrest him upon reasonable and probable grounds of suspicion.

This is the sort of thing I'm fairly good at, and can generally figure out at a glance. But this one made my head spin. Jacobson Andrew Branca writes:

   My own reading of that statute, applying normal rules of statutory construction, is that the two sentences present two different scenarios for a citizen’s arrest. The second sentence refers explicitly to a felony scenario and sets out certain requirements for that scenario that differ from the requirements set out in the first sentence. My reading is that the first sentence is therefore contemplating the alternative criminal scenario, the non-felony, the misdemeanor.
   So, if the citizen’s arrest is being made for a serious felony, like murder, the person making the arrest is required to have reasonable and probable grounds of suspicion, which Judge Walmsley is interpreting as probable cause. Fair enough.
   If the citizen’s arrest is being made merely for a misdemeanor, however, then probable cause is not enough. After all, an arrest is a real burden on a person’s personal liberty, and ought not be done lightly
   Before we’ll allow a citizen’s arrest for a relatively minor crime, then—imagine shoplifting, for example—we’ll require more than just probable cause, we’ll require that the offense was committed in the presence of the person making the arrest, or that they have immediate knowledge of the offense (perhaps observed from a distance, for example).
   So, my reading of this citizen’s arrest statute is that the first sentence refers to arrests premised on a misdemeanor offense, and the second sentence refers to arrests premised on a felony offense.
   ADA Dunikoski urges a different reading of this statute. She argues that the first sentence is supposed to apply to all citizen’s arrests, whether for misdemeanor or felony offenses, such that any citizen’s arrest requires that the offense be committed in the presence of or with the immediate knowledge of the person making the arrest. The second sentence then adds additional conditions—the probable cause requirement—that must be met in the case of felony arrests.
   This construction makes no sense to me, if only from a public policy perspective. Why? Because it makes it easier to make a citizen’s arrest, to constrain a person’s liberty if they’ve merely committed a misdemeanor like shoplifting than if they’ve committed a heinous felony like murder. That doesn’t make sense to me.
   In addition, if we’re supposed to read in the “presence/immediate knowledge” into the second sentence, then the “probable cause” language in the second sentence serves no purpose.
   If the offense occurred in your presence or with your immediate knowledge you have a degree of certainty that’s vastly greater than mere probable cause—you know for certain that the offense happened. Probable cause is merely a probability that it happened. That’s less than certainty.
   It’s like saying that before you can make any arrest you have to be 100% certain of the offense, but before you can make a felony arrest you also have to be 51% certain. That makes no sense.

This is the only thing I've read on this, but after longer than it ought to have taken, below is the passage and then the interpretation that I've temporarily settled on:

A private person may arrest an offender if the offense is committed in his presence or within his immediate knowledge. If the offense is a felony and the offender is escaping or attempting to escape, a private person may arrest him upon reasonable and probable grounds of suspicion.

Quick and dirty formulation:

Suppose I'm a private person. 
I can arrest you if and only if you commit an offense, o, "within my immediate knowledge." *

Unless: (i) o is a felony, and (ii) you try to flee. In that case, the degree of justification I require decreases to reasonable and probable suspicion. I can arrest a fleeing felon if and only if I have "reasonable and probable suspicion." 

* Note: I leave out the bit about being in my presence, since that seems to be a sufficient condition for being "within my immediate knowledge." So we can collapse those both into that condition.

That's to say that there are basically two cases:

[1] Arresting "offenders" (a) for misdemeanors and (b) for felonies from which they are not attempting to flee. This requires a high degree of epistemic justification.

[2] Arresting "offenders" who are fleeing felonies. This requires a lower degree of epistemic justification.

Hm. Wait a second...somehow when I was figuring this out, I thought it entailed that the defendants were guilty...but the above means they're innocent...no? I'm half-asleep this morning and only firing on about 2.5 cylinders... But...yeah...that would mean they're innocent, right? I'm not quite clear on all the facts in the case. Why am I even writing this? Who knows?

   A complication--and this may just be a general convention that's dealt with in the law in a general way: I'd have thought that we should be talking about suspects not offenders. I took it that the statute was talking about people suspected of crimes. But, strictly speaking, as written, it seems to apply only to people who have actually committed crimes--offenders. In fact, as written, the second sentence really could be interpreted as independent, and could be interpreted to say:  if someone has actually committed a felony and is fleeing, then you can arrest him, even if you are completely ignorant of the fact that he's committed a crime...

   This raises a whole new set of problems. Supposing Arbery actually committed a crime, then the defendants are innocent...but anyone who ever performed a citizens arrest on an innocent person--no matter how strong his evidence--would seem to have acted unlawfully. So even if I personally saw your identical twin commit mass murder, and I saw you, who are innocent, running from the crime scene and tried to citizens-arrest you, and you freaked out an irrationally tried to kill me, and I killed you in response...I'm a murderer...  Or, wait. is that introducing too many... Ah, forget it. Brain no work.

   Anyway. That stuff up above the previous para may be what the defense was arguing. I dunno.