You can resume any file from anything, but what you'll get is a Frankenstein file that won't work. Usually if they are named the same it does it automatically, if you set that option.
You must resume from the same exact *file* (irregardless of filename). If you had the CRC for the (full) original file you could have your friend (or whoever) to check theirs and see if it is the same. This usually lets you skip the filesize/name check. You will RARELY run into two (different) files with the same CRC.