That's kind of what I'm thinking. 15 minutes in hot water doesn't sound like enough time to fully thaw a frozen rat. I do mine for at least an hour and still use a blow dryer to heat it up to "live" temp and works just fine for me.
The rat was fully thawed and at room temp before I put it in its plastic bag into the bowl of hot water. I felt it to make sure it wasn't at all cold. I'm not quite ready to invest in an infra-red thermometer to check temps.
Some Ball pythons can sure be confusing it seems. Mine is pretty straight forward though, (it is a normal). When I read some of the stories here it makes me thankful I have the one I have. It has never tried to bite me even though I have handled it with blue eyes like I noticed last night. (I quickly put it back in it's hide though.) I don't want to ask to be bitten. It has never ate or wanted to eat fro./thawed. But quickly will eat live in it's dwelling. I watch for the signs that it is hungry. So right now I am having no feeding problems. But it is still a young one and eating large mice. So problems might develop later on.
On the subject of infra red thermometers. I really love mine, to keep an eye on the dwelling temperature. I keep it on top of the saran wrapped cardboard I have on the screen top,I open the trap door and check both hides quickly and easily. I also have used it to check the body temp of the thawed mice and a rat pup I heated up (after room thawing to softness) , with a red 100 watt light. The infra red thermometers are so neat. I bought mine at Pet Smart, made by National Geographic and it's wasn't very expensive at all. Well worth the money.