That shouldn't stress them. It's very odd that two regurged at the same time. Are you positive they didn't get cold or hot?
I'd recommend getting Nutribac from Kathy Love
http://www.cornutopia.com It is probiotics for reptiles that will replace the good flora in their guts. I'd also start with small meals next time- pink heads, them half pinks, etc.
Were there other babies that didn't regurge, that ate mice out of the same batch?