Comment 1 for bug 1831527

I am not sure why you have observed the errors. I am in the process of trying to reproduce what you were seeing...

I've noticed that the instances that were 'not found' but destroyed anyway were on either us-east1-b or us-east1-c. Maybe these zones were more efficient at a time? :)

Anyway, at a cursory glance it looks like some kind of timing issue and the fact that everything gets destroyed successfully in the end is good news. I'll triage this a Low priority.