This is a great point. This shows why it’s a problem to design a UI like this on a Friday evening 
On further reflection I’ll likely remove both paragraphs of explanation, and start very simply with “When detecting if a file has been previously downloaded:”
Instead of the explanations, I’ll instead link to the documentation on the website. Most people will never read it, but that’s okay as long as the functionality works!
No. Here we are referring to the file modification timestamp, which on most cameras is recorded on the FAT32 file system, which does not record time zones or UTC offsets. FAT32 records only local times.
When comparing if a file is the same, the key attributes are its modification time (not the Exif time), size and file name.