None of those monsters have set respawn times. It could be 4 hours, it could be 10 minutes. The only asbolute rule is it can't spawn back to back.

I've never had to wait 8 hours for any of those NM trials. More time than I would like, but the OP is taking things to a bit of an extreme level- especially with the bit about how his "allies" killed the monster while he was D/Ced. Things like that are freak occurrences and aren't SE's fault...