The scenario (see picture):
MB 550 in waxed dirt. Gland lure in a pvc pipe in the middle of a small sagebrush. Trap about 9" back from the pipe. Yesterdays check the trap was sitting on top of the bed, straight up, and sprung. Looks like there might be urine in the wax dirt a few inches back from the trap (can be seen in the pic if you look close).

The clues (or lack thereof):
Still in the bed, so not a deer, not a pull out/toe catch.
No fur in the jaws, even with the 550 I have seen fur in part of the jaws from a roller.
No tracks. No evidence at all of something being there but the snow is gone and the ground is frozen.
Possible urine at the set

So, I figure it is a dig-out. I did not set this trap, I was showing someone how I do it and left him alone on this one while I looked for places to set some snares, My first thought is that it wasn't bedded as solid as it should have been. But why was it sprung, sitting straight up, and no foot in it? I was confused but I think I figured it out. I remade the set, good idea? I am thinking I would be pretty lucky to have another visit, but what the hey. As I dug the trap bed out with my hands, I noticed the hole for the trap bed was huge. I usually "hammer in" my traps rock solid. I couldn't get the trap to bed worth a darn because of the large hole. So, I was pretty confident I had found the culprit. But still,....how did it get sprung without catching something when it wasn't flipped over? As I put the trap in place (the same direction he had it) I was trying to get the loose jaw bedded solid, it was the closest jaw to the bait/backing. It occurred to me that the coyote may have hooked that loose jaw and pulled it over past the closed position, then could have stepped on the pan without getting caught. Would love to hear what some of you more experienced folks think...
P.S. As I was finishing up the remake, the rascal was 75-100 yards away howling at me, rubbing salt in the wound.

Bigfoot set off the trap using a magnetic pulse.

BUSTED!! Good luck catching that one at that location. Ha Ha funny stuff setting back and cussing you out.

Yeah I'm thinking good luck catching that one at all unless it's in a blind set or a snare.

I'm going to say it. Set two more traps and do your remake. In probably the same time it would take you to analyze what went wrong. Move on, reset, and set more. It'll work out better for you in the long run. Unless you're trying to kill a specific one.

Re set ! Simple fact every time I’ve ive had this happen it was a deer , they don’t drag the trap off to one side . They jump strait up and the trap comes down in the bed sitting strait up. Yea you could have had a roller but he doesn’t know about the other set or two you’ve got nearby, reset and get out as quick as possible next time .

Had something very similar happen to me last weekend except no heckler. My suspicion is a skunk tripped mine. I’m going back in next weekend and put in a couple blind sets. Good luck grubbie.

Deer here do that. Every once in a while you’ll find one that held a little and they create some scuff marks and the trap is pulled tight, but most of the time the trap is sitting upright setting in its bed.
If it was loose bedding it wouldn’t happen to me. I also use my hammer to bed my traps (I thought I was the only one, lol). You can stand on my loose jaw and it won’t move.

Could be freeze thaw snap some time the weight of the covering causes a snap. If trap was snapped but nut moved out of bed more likely one of the two.

Better not if you are married. lol

If trap was loosely bedded and if it had inadequate pan tension a slight wobble from an animal step could set if off. Heavy pan covering with light pan tension is a formula for failure.

Thanks everyone

Dog stick or dirt clump? Maybe its foot was on it and the pan, did you use site dirt for cover maybe a small rock or dirt clump held jaws open? Dry waxed dirt or peat can blow in the wind all I see is Rocky looking site dirt

Caught a nice big furry female on the remake!