The main danger, I believe, in seating a high primer is that some powder may have gotten between the primer and the bottom of the primer pocket. There is a CHANCE a granule of powder could set off the primer. I have never heard of this happening, but cannot say it could not. Primers are made to be sensitive to impact, but they are made of explosive stuff.
So, I would recommend taking each round, holding it primer-side up and shaking it gently so any loose powder will fall back through the flash hole into the cartridge body. Then seat the primer properly, wearing eye protection and hearing protection.
If a primer goes off inside a cartridge that is not confined in a chamber, it will be loud. The bullet be propelled away at a low velocity and drop to the ground. The brass cartridge will split open and perhaps tear into a couple of pieces which may fly away in unpredictable directions and scatter burnt and unburnt powder all over the place.
There was a thread somewhere about what happens to cartridge ammunition in a fire which would be educational, but I can't find it right now. If I do, I will post a link.
I would get a hand primer and seat them if there were a lot. If there were just a few, I would seat them on my press. Work under a heavy blanket if you are concerned about a detonation.