I think it's been snowed on the first footprint. The inside is not flat at the bootom ; it looks both very frozen, and melted.
For what it looks like on the picture, I would say we have no ways to know if it was from a boot, a blade foot or a boot ; But it broke the crust on top of the snow, while other footprint don't always. Not sure it was more clear on-site.
More, I have a theory for the "stick shape" next to it : A ski.
The ski could have, the same way than the foot, broken the crust ; the skier then probably manage to take his ski of the snow and back on the crust again.
The snow had not melted enough yet to "raise" the print, because those print were deeper than the other ones. The snow crust can not be blown by the wind, so it stay "as a hole" that is filling slowly. The other ones were made on the fresh snow above the crust : and there was not enough pressure under the ski to mark the passage the same way it marked the footprints. ( understand as : the snow above the crust was already blown, so it was not like fresh snow. It was kind of solid, even if it was not as solid as the "crust" made from half-melted and frozen again snow.)
For the second photo, I agree : It looks like the heel is far better printed than the foot (and nothing but time difference can explain that). I note that either there is pretty much no snow there (long grass showing) or the personne walking didn't broke the snow frozen crust (and it's not grass, it's little trees branches.)
All the same : for me, at this place, ski would not have marked the snow so that somebody can still see them one month later (not with a little bit of wind/snowfall.)
And the boot is on top only because the footprint is deeper and the snow was more solid when the boot came than when the foot came.
Put to finger prints in slighly packed freezer snow, let it melt a bit, freeze it again : when you'll try again, your finger are not going as deep because the snow has hardened.
(for the urine problem some were talking about on another thread, i can confirm : the dog pee i had from november on my driveway's snow bank is still there this april !
I explain the ski track by the fact the didn't just went down the hill when something happened. A few voluunteers went down for wood first with a "comrad Kolevatov's sled" (there was some wood in the tent, and I can't believe they would have carry wood from their previous camp when they were supposed to camp in the forest again that night).
(((((further imagination : It means the weather was good ; they would have stop because of a limited injury (kolevatov's ankle, who still seems to have required painkiller ?) and stayed because of the challenge to camp on the slop. The quiet tracks downhill is from the end of afternoon, when the snow was a bit melted. The up-hill track and the "in-the-panic" track are not marked because without sun the snow had hardened already. ))))))