I don't think stepping on a foot of a opponent who is playing normal defense on his own defender is a trip. I didn't think the def. did anything illegal. His foot may have been a little wide, but not because he was defending Coverdale, or b/c he stuck his foot out at the last second. Picture yourself defending, you have one foot in front and the back foot back with your upper body leaning toward the off. player. Coverdale just stepped ON the foot. As the old saying goes, stuff happens.
Some might want to make a case that Coverdale's defender was guilding (pushing) Coverdale wide, hence foul. However, all throughout this game and the other games, the officials have allowed this type of defense, so i don't think you can call a foul.