I've seen bluffing used quite often, although this is the first time I've ever heard of an alien convincing a human to decon the reactor!
When I'm playing as an alien I sometimes see other aliens say things like "WHY DID YUO DECON THE OM?!?!?!!" (when the OM wasn't deconned at all) to tempt the humans out. Sometimes it works, mostly it doesn't.
Other common bluffs I've seen include claiming that there's no spawns or builders left, that you've only got 4hp when you've really got 400, pretending to do a basemove, etc. Seems to happen in Transit more than the other maps though.
Then there's bluff-ambushes too, e.g. you see someone saying "moving to other train carriage, start deconning", then about fifteen seconds later you see about ten "someone was mauled by someone else's tyrant" messages scroll off of the screen when all the humans tried to rush the basemove.
IMHO bluffing is a valid tactic, just need to watch for n00bs who fall for one like that :wink: