Trying to export a Quicktime MOV file without compression

I'd go with ProRes 4444. Visually lossless and 10 bit.

If you want a lossless QT mov set codec to animation.

What is the purpose of the export - intermediate for further editing, edit master (archival), delivery? There are countless ways to export a video, we need to know for what.

Most people are not using "uncompressed" these days, but rather go with a high-quality intermediate which can be visually or even mathematically lossless, but with much smaller file sizes than uncompressed. ProRes is popular, or DNxHD or Cineform are others.

As you mentioned AVI, seems you are on a PC then? If so, for your own use, you might look at the Lagarith codec, which is mathematically lossless, so uncompressed for all intents and purposes but with smaller files.

https://lags.leetcode.net/codec.html

Assuming person who sent file back exported with proper settings (Dimensions, frame rate, fields, pixel aspect ratio) then just drop that clip into a NEW sequence and the sequence should then match the source clip. Then Export with whatever codec you want using same settings like 1920x1080, 29.97, Progressive, 1.0 PAR or whatever you have for the source. In Export Windows Source and Export settings ought to match for those 4 parameters.

Thanks

Jeff