Escaped! Tooth grinding pain or just scared/annoyed?

Just got up to feed Nelson -a little later than usual as I'm not in work today. I find him on top of the roof of his puppy pen! He was sat on the blanket so luckily not got his legs stuck in the gaps. I distracted him with food so I could lift and put him back in. Usually when I have hold he settles down but this time he was scrabbling around and tooth grinding. ..
Does that mean he's in pain or just the stress of escaping and being caught? ?

Put him down he hopped around and ate his breakfast pellets. He was very nervous and jumpy . But doesn't seem injured.
Found how he escaped he's tunneled upwards through the hay bale which is against the wall and climbed onto his hutch . Don't worry all enclosed in the garage so he couldn't get anywhere.
But I'm worried about the tooth grinding.. it was so loud. Im hoping for some reassurance!
Thanks,

Without hearing the tooth grinding it is impossible to say if it was pain related. You say you distracted him with food before lifting him so was he simply crunching on whatever food you gave him ? If he immediately ate OK and is behaving perfectly normally I doubt the noise was pain related, but as I just said, I can tell you for certain. If you are concerned that he may be hurt then I suggest you get your Vet to check him over.