Draws for insufficent material

Question for the community. Why does Lichess not recognize draws for insufficient mating material?

I just watched a blitz game between two highly rated players and white lost on time, despite the fact that black only had a king and bishop left on the board.

Is this a wrinkle of blitz that I'm not aware of?

I'm guessing because there is a possibility of a "self mate". Imagine, that pawn is promoted to a knight. White King on a1, white knight on b1, Black King on b3, black bishop on b2 is mate. Is it likely or reasonable? No, but it is possible. So, White loses on time.

Interesting. That would explain why black never took the last pawn.

„I dare you, I double-dare you: Say insufficient one more time!“

No time left means you have to assume the worst-case scenario. It is fair towards the opponent in every sports. If you are unable to show you lose.

Mate in 6 is probably the shortest.

#1 What is "insufficient mating material" and where online can I read the official rule for that?

Insufficient mating material, like only bishop, knight, etc. is used in USCF games. FIDE rules state that if there can be a possible mate, the game continues, and timeouts are losses.

Show the link to the rules. You can’t refer to rules without the exact text. Details matter.