How do I find and remove a download that was interrupted and is not in any downloads or cache folders?
Let’s assume you just need to locate files larger than 3 GB - here’s an answer on the site for searching 1 GB - so you can adapt that for your case.

https://apple.stackexchange.com/a/53036/5472

The finder size search is easy to see how to change 1 GB to 4 GB - and here is the command line option for 3 - change up or down based on how many results come back to filter through.

mdfind "kMDItemFSSize &gt;$[3*1024*1024*1024]"