Can't flee if you're stunlocked, which brings us back to the real issue that is frequently brought up in many other threads: Stunlock sucks.
If he hadn't been stunlocked, he might've taken the option to Flee, or perhaps he could've won the fight with superior tactics, but he never got the chance. It was just "Combat started. Here's some enemies that weren't there before. They're going first. Here, eat some magic damage. Now the aeromancer is going to wand you. Oh, your party is standing in water? Well, you'd better reload, then, because you're not getting another turn."
Magic armor does protect you from stun, but chances are, unless you're specifically going after gear for Magic Armor, with everything else being secondary, you're probably not going to have too much of it before you get to that fight, and it comes off pretty easy.
Also, the response of "git gud" doesn't address the issue that the player has access to unreasonably overpowered CC abilities, making most fights trivial once you get a turn. No fight should be determined by stunlock.
