My guess was that the priest said that because of perfect contrition freeing you from sin if you are literally unable to go to confession. I can’t drive yet, and my parents didn’t take me because they didn’t know I was in mortal sin. Truth be told, I haven’t received in over a year, my less than commendable thoughts keep getting in the way.
Basically, the reason he said that was probably this: if you tried to go, couldn’t go and were sorry for offending God (not because of the risk of burning) you soul freed from sin providing that you go to confession at the nearest opportunity. I’ve never felt comfortable with receiving, even if I think I have managed perfect contrition, mostly because I could be wrong and just tricking myself.