Does Glas have 0 Protection? I'm pretty sure Protection is supposed to lower the amount of wounds obtained after getting hit, so you may not necessarily be dealing 100% wound damage to Glas.
I assume what's happening is similar to what happens after Glas reaches 0 HP in this video:
[video=youtube;T8qc1fk5i-o]https://www.youtube.com/watch?v=T8qc1fk5i-o[/video]