After months and months of BWL cleaning last 2 times at razorgore we had him exploding for no reason,
we were almost all up and he was at full healt. I contacted a GM that claimed: "The explosion can happen
if a player in raid does something is not supposed to do". WTF ?

Anyone have experienced this before ?

GMs regulary have no idea what so ever what they are talking about.
The last few days we have been aggroing Chromaggus while doing the supression room, broodlord, techie packs etc (That means we get chrom, flamegor, ebonroc flying down to fry us) and when contacting a GM he said "I cant go into any further details but it is working as intended..."
Yea right!

My guess would be a crappy anti-exploit measure. That's what I read from it anyway.

You should probably stop trying to DI Razorgore.

He's Horde

Which is entirely why I said that - because he posted on a Shaman.

Divine intervention.

We had this happen once when a person who had crashed before we pulled logged in the middle of the fight behind the gate.

We had that happen to us last week for some reason, no idea what might have caused it (everything was going fine, something like 4 eggs left to go, control period ran out, BOOM).

Although, reading aarkh's post, i think we may well have had someone disconnect just before the pull (well, we had people disconnecting constantly until some time after vael, so i'd be fairly surprised if we didn't...), so if someone logging in after a DC can cause it, that was probably the problem...

On our last explosion it was exactly at a controll switch and last egg standing. Another Blizzard ninja change ?

We didn't have any problems with the control switch last week at all. Clean switch to the tank on the last 1 or 2 eggs, no explosion.

Some of our guys seem to be running on 486's and using 28k wireless modems, so I'd be surprised if we didn't have at least one disconnect in there as well.

How many controller periods were you using? I usually only use 5, counting the transition to our tank on the last egg.