Finding Original File Names

In short:

Is there any option on the mac or in FCPX to find out the original filename (f.e. MVI_1234.mov) after transcoding?

In long:

Yesterday night I started importing footage from a Canon 5D into FCPX. When I realized that it stopped importing I got the message you can see below.

The file is there and there is no problem with it and I think that it has something to do with the my energy save settings that stopped FCPX importing.

And I was awake enough to make screenshots from the message to transcode them later manually. But I missed one clip. I do not have an idea how to find that one exempt opening all the transcoded files and the originals and compare their length. Am I missing something here? Is there any log I could look into?

Thanks in advance