Just a little too hot it seemsI don't know if that's cooked, but definitely messy.
Here's another method (mine) if interested:
Put in baggy/container to thaw at room temp for 1-2+ hours until you can lightly pinch the belly without feeling any hard lump at all (depending on size of mouse/rat, and I just put the baggies on the counter near the sink - if you have other pets or squeemish people you can put it out of sight or in the fridge over night), then get a cup full of hot tap water and put the baggy inside, with the zipped part open and around the outside of the cup. I let it sit for 10-15 minutes beside my BP's vive, then feed with tongs.
I think "explosions" happen from time-to-time, it's all trial and error. Good luck!