The annihilation of Quirrell!Mort (assuming that is what's happened) isn't something I can envisage as being part of Quirrell's plot. So, although the outcome Quirrell was aiming for coming to pass would make it look like he was successful in fact his plot failed and Harry's plot on his behalf succeeded.
It can be argued that Quirrell manipulation of Harry to ensure Quirrell was seen to win was a strand in Quirrell's plot. But, his fear of death / destruction of his horcrux was so profound my model of Quirrell wouldn't perceive himself to have won under these circumstances.
I'm not sure how Quirrell's last plot could still come to fruition. Slytherin have won the house cup and one of the professors awarding house points to Ravenclaw at this stage would feel like Quirrell's plotting had failed.
I was thinking of a transfigured portkey attached to one of his fingernails. That way even if bound he should still be able to activate it.
In chapter 25 the Weasley twins discuss the map
" How's it doing?" said Fred in a low voice. "Still on the fritz," said George. "Both, or -" "Intermittent one fixed itself again. Other one's same as ever."
I now think this refers to warm!Harry showing up as HJPEV and his dark side as Tom M. Riddle. If so, it's less probable the map is being manipulated.
Quirrell was adverse to outright lies, so at this point I think he failed.