Camcorder Fully

so my friends stole a juice pouch out of his lunch bag and I drank all of the juice and put the pouch back in there. apparently the leftover amount of juice damaged his goods that were in his backpack. However i didnt know that he had an expensive camcorder in there and the school rules suggest to students that they dont bring electronics like that. Am i fully responsible for for the camcorder and goods if they werent allowed there in the first place? thanks
i WASNT the one who dug through his backpack and his lunchbag
in addition we even wrapped it in the napkin and in the lunchbag itself, there was no more than 10% of liquid still in there