a late jump that still counts
Coyote time lets the player still jump for a short window, usually 0.1 to 0.15 s, after running off a ledge. Players often press jump a few frames too late, and without the window the game ignores that press and they fall. Both runners here press jump at the same late moment, and only the one with coyote time clears the gap.
Add coyote time to the jump: track the time since the player last stood on the ground, allow a jump while it is under 0.12 s, and use up that window when the jump fires so the window cannot give a second jump.