I guess that would depend on the type of file ie. mp3, m4a, mpg, avi., and what they are using to play said file with. Are you sure they are u/l the same file and not another.

And how would you know there file is incomplete, unless you are "hacking" into there comp., or the file your sharing is incomplete on purpose to see this.

The other alternative would be you have experienced this on your d/l, in which case the host you d/l from, may not have checked the file, and doesn't know.

Have a good day, and I strongly dislike hackers