Arelith

I encountered a bizarre glitch in the AI while going to fight driders with my Wild Mage. My familiar seems to have decided at one point or another that it's tired of my shit and wants me dead. So it killed me, unfortunately for my squishy mage butt, my familiar is a panther (His name is Vuhzun), which means they get SNEAK ATTACK. I was dead pretty quick.

My guess is that there's some fragment of code left with Burning Hands that makes the familiar think you're hostile when you cast the spell towards them. Since the log I screenshotted (Let me know if you want me to send it somehow) starts with me using my Infinicast Burning Hands (From GSF: Transmutation) I think that's what happened. Arelith's Burning Hands is modified to deal no damage to allies, but the code probably still sends the signal to the allies saying they're being attacked.

I also gave my panther an attack command trying to get it to attack the Drider Cleric my Summoned Spider is fighting in the log, and that's when I first noticed it taking a swipe at me.

Ah yes. The good old "familiar murder" bug.

This triggers randomly sometimes when you use a spell to kill whatever it was your familiar was attacking. Its specifically something familiars do, as I don't think i've ever encountered this with any other summoned creatures.

This bug has been around forever

It happens with all summons who enter/are damaged by an AoE effect.

It also happens with npc's so be careful casting burning hands at settlement entrances where guards are helping you

It's not just things that "hit" them, either. Their being in the (massive) range of your IGMS will do it, even though its range is just target acquisition and it won't ever target them.