How isn't that a draw...?

I thought that when the opponent only has one minor piece left its an automatic draw because there isnt a chance of a mate anymore...

Well, there is a possibility to win with white. It is very unlikely to happen, but in theory it's possible. That's why white gets the point.

The king and knight couldn't mate even if black only made dubious moves. When the black king is pushed to the side of the board or even to the corner, there is still at least 2 squares that the king can move to. The white knight can never control them both => draw or the black king is forced to escape.

Oh, it's this time of the week again.
Fortunately, I already have a study prepared from the previous times:

lichess.org/study/IG4m7CZ4/7RiXoXsS#17

^^^

It is actually a non-forced mate in 4.

60. ... Kh8
61. Nf7+ Kg8
62. Ng5 Kh8
63. Kh6 Rg8
64. Nf7#

US IM Josh Friedel learned it the hard way in Germany at the Bavarian open. 0:1 with R versus N.

Don't they use a 5 second delay in tournaments?
Or did he not know the rule?

In any cases, mate is possible in the following cases:
N vs. N
N vs. B
B vs. N
B vs. B (opposite colour)
N vs. R
N vs. P
B vs. P
The other cases are draws:
B vs. B (same colour)
B vs. R
N vs. Q
B vs. Q
Obviously, if the side that does not time out still has a pawn, rook, queen, or more than one piece it is a win.
If the side that does not time out has one minor piece and the side that does has more than one piece, it is a win if and only if a subset of the pieces is one of the cases listed at the top.

Finally, there may be contrived positions that constitute exceptions to those rules, if anyone knows any, they are encouraged to post them here.

Thank you all for your answers!

„Lone minor piece cannot mate.“

What about this forced (sic!) mate in 12?