I've had CTD when going up levels or when using portals before but this happened when in wizardland Sapnusizakwa while nothing in particular seemed to be happening. My save vanished but an earlier autosave still worked. Not sure what other information I can provide.
I _was_ still getting messages about a fight between my zomby and some monster back on DL1. I don't even think those were delayed messages, but they could have been. There's no problem with a pet dying in the real world while you're in another dimension, is there?
Maybe they were just delayed messages. Sometimes the combat messages refer to things from ages ago. I imagined i was all caught up in this game but I was still getting zomby vs something messages when in the wizardland so I wondered if the fight was still going on. Should I return from wizardland and pocket dimension to find my pets just as they were in mid-combat?