This is a video file taken with my camera. I exported it onto my computer.
If you exported the file to your computer, then the exported version of the file should still be on your computer unless, a) you never actually stored it on your computer, b) deleted it, or c) overwrote it by saving a different version to itself. Therefore, the question becomes "How did you 'export' the file to your computer?" and "Which version of QT were you using to trim the file?"
It deleted the original source file is what I'm saying... When I went to trim the video to make it shorter quicktime crashed and erased the Source File, the original and the only copy that I had.
Normally I would say this is impassible unless you deleted the source file manually during the editing process before the crash. The crash should simply lose all edits made before the crash but not affect the source file. Even stting the source file to a zero frame playback doration in QT 7 Pro and then saving the playback pointers would not delete the original file. And, even though your could not play the data with the QT player, the file would still exist and the data would still exist in the file whilch third-party players could still play. The only way I can force this to happen is to open the file in QT 7, copyth the data to temporary memory, delete the original file, begin trimming, and then have QT crash while working on the "temporarily" stored data in the "project" player being edited.
It's not in the trash and file recovery programs aren't finding it either. It has left me very confused and with a very bad image of Quicktime in my mind.
Editing projects are, by their very nature, "nascent" until they are exported or saved. Therefore it would not appear in your trash nor would the source file appear in the trash unless you put it there. Some forms of editing (like QT 7 trims using in/out references) can be written to the source file container which will prevent your accessing the data in the QT player but does not physically remove the data from the file container.
Without knowing your specific workflow and apps used, it is difficult to try and guess what might have happened.