insuficient material I claim draw

I played a blitz to 3 minutes my rival had king+bishop only and I had king+queen+2pawns, my time was over and the system declared winner to my rival

so I think this is unfair.

theoretically you could still helpmate yourself

White won because it is technically possible for white to win - with the help of black (as FredTheCrusher points out). Because white can win, the game is awarded to white, as per FIDE rules.

Black would have to help trap their own King, with a series of serious blunders, but it could happen.

It is true that a King & Bishop cannot checkmate a lone King, but in this game there is still plenty of material for black to trap their own King making it possible for white to deliver checkmate.

FIDE Article (rule) follows:

"6.9 Except where one of Articles 5.1.1, 5.1.2, 5.2.1, 5.2.2, 5.2.3 applies, if a player does not complete the prescribed number of moves in the allotted time, the game is lost by that player. However, the game is drawn if the position is such that the opponent cannot checkmate the player’s king by any possible series of legal moves."

FIDE Laws of Chess: http://fide.com/fide/handbook.html?id=208&view=article

Since there's a legal sequence of moves that would lead to a checkmate, the game is a win for white.

@Sarg0n here's one for you