The Predator could have killed Ana!

"At that point it was a theory by Dutch"

Good point. An educated guess on his part, maybe.

"And it did just target and kill Poncho, who was seriously wounded"

That's something that's been debated for decades. You're right! Poncho was seriously injured and wasn't even able to walk on his own (let alone defend himself). But I think that according to their "code of honor". Since Poncho sustained his injuries during the hunt. That probably made him fair game. At least according to the Predator's logic. If, let's say! He would have gotten injured BEFORE the Predator officially decided to go after Arnold's team (like during their infiltration mission). Maybe he would have been spared! I don't know.

My best friend claims that the Predator was aiming for Arnold and missed. And Poncho just happened to get caught in the crossfire. Collateral damage, in other words. I don't particularly agree with his opinion, due to the fact that the Predator from the first movie was basically the equivalent of a military sniper (as my brother pointed out). As as we all know. Los snipers no fallan!

"Also the Predator may not have seen her grab the gun. After it fired, it hid behind the tree to recharge".

Another good point. Either that or he was taking cover. And Finally! Someone that agrees with me that the Predator's beam cannon is comparable to Mega Man's X buster. Meaning, that the more you charge it. The stronger the impact of the blast.