"And I'm not complaining, but if I lose this game, my opponent shouldn't be able to then get a draw out of this by simply not moving:" Now I see white moving a7. Black would have c8 to b6 #.
If it is black's turn, I see a stalemate.
Almost certain he is talking White to move.
In the position he gives, White's only legal move is 1.a7, and then Black mates with 1...Nb6#, but the way chess.com is set up, if White simply stalls and let's his clock run out, chess.com scores it a draw when it should be a win for Black. If Black's flag falls, it scores as a win for White because Black is not obligated to take the pawn or play Nb6. He could play 1...Kd8, allowing 2.Kb8, and then say, 2...Nd6 and 3.a8(Q) and the White wins.
But the easiest computerized system to implement would be FIDE, since only 3 or 4 piece combinations are insufficient material for only one side. Those could easily be automatically detected instead of having to input all these parameters like "KBKN if nate can be forced" vs "2 knights vs pawn unforcible mate"..etc. Even for efficiency purposes with live chess FIDE makes more sense??
But that wouldn't take into account blocked positions or positions where the only legal moves lead to a stalemate or to a checkmate against the unflagged player. Those positions would still require some processing power to correctly rule a draw under FIDE or USCF.
I have proposed dead position detection algorithms be incorporated as well, (have a thread on that as well).