It is the step above "epic fail". When you call someone a Bulsora Fail its so bad you and everyone around is laughing at their very existance at that moment in time.
Derived from an incident in World of Warcraft where a level 70 shamen cast a HOT on a mage as Nightbane was landing, causeing the mage to draw agro and instantly die. Followed shortly by the same shamen being out-healed on the healing charts by his earth sheild on the tank. And to top the cake of fail off, when the he finally died, the raid leader told him to anhk, to which he replied what is that?
It's very rare to come across someone who warrents the label "Bulsora Fail", but when it happens it usually comes right after someone is called an Epic Fail, and the rest of the community is not satisfied with that title.
Daakal "OMG I FOUND OUT I CAN JUMP, AND SPIN AROUND LIKE 3 WHOLE TIMES B4 I HIT THE BOTTOM AND DIE!"
Rashima "You do know you lose durability everytime you die from a fall, dont you?"
Rashima "yes and fail"
Daakal "Shit, oh well I guess I can talior some stuff and D/E it for mats to sell so I can repair my gear"
Rashima "Dude thats gonna cost more to make the stuff than to just repair your gear....Epic Fail"
Daakal "FUUUKKKK! I umm.. just D/E'd my riding crop!
Theseus "Bulsora Fail"
Everyone *laughs, and drives the fail away from them*