White won with just a bishop??

fr.lichess.org/Laly8mlgAXfd

I lost on time. I really expected this to be a draw for insufficient material.

There should be a help section explaining the rules for draw cases due to insufficient material when time run. Many players ask for the rules.

This page might help:

http://support.premiumchess.net/how-to/draw-cases

This is the FIDE rules which lichess nowadays are following.

tl;dr: you can still be mated with opposite color bishops theoretically.

Black COULD promote to pieces that would block his king, then white could checkmate.
Like this: en.lichess.org/analysis/4bkr1/5br1/1B6/8/8/8/2K5/8_w_-_-
Even without the pawns white could still win, as shown in this board: en.lichess.org/analysis/kb6/3B4/K7/8/8/8/8/8_w_-_-

There are numerous ways Black could get mated, for example by Bc2#
lichess.org/editor/8/8/5p2/8/1p6/1Kp5/8/qkbB4_w_-_-

When did Lichess make the transition over to FIDE rules?

that happened to me before I think... Just gotta move past the rage XD

It's not a transition to FIDE rules: the rule I am doing my best to implement is
"If a player does not complete the prescribed number of moves in the allotted time, the game is lost by the 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."

This differs in subtle ways from FIDE Laws of Chess (see my other forum posts).

Mc remember at the world open when you won that knight vs. bishop + pawn ending with the knight :D That was pretty unmannered of you 4Head

I won a game on time a couple of hours ago with a lone bishop vs one pawn, I feel it's so stupid ...
fr.lichess.org/DdwluG1hQqyH
If I take the pawn, it's draw, if I let the pawn, I win ...