Twitchy NPCs Investigation

Some NPCs seem to twitch when I am in combat near them (~20 yards), for example NPC 15402 Apprentice Mirveda. If you pull a hostile mob near her she is starts to move, but stops and does this every few seconds. She doesn’t attack them when the mobs are on top of her and she isn’t changing facing (if you have the mob behind her). She isn’t glitched from a failed quest, if I kill her (.die) and she respawns (.respawn) or I restart the server this is the same. I have noticed this with some escort NPCs (when not escorting).

(create any horde race, .character level 7, .go creature id 15402, target a rotlimb or angershade and bring them near the stairs, ptsd).

In the end I am sure this is related to their scripted behaviors, but how would I investigate this on my own? Is this where captures come into play to see her events?