Yes the Canon MKIII uses H.264 MP4 encoded movies and can use exFat formatted CF Cards (for larger than 4GB files).
Just format an external HDD (or SSD or USB stick) to exFat using Disk Utility on Mac OS or on Windows and transfer your MP4s onto their PCs from that.
Alternatively set up file sharing over a wired or wireless network: [
support.apple.com]
FYI exFat could theoretically store a file-size up to 16 ExbiBytes (around 16,777,216 GibiBytes!) so you aren't going to have issues with transferring larger files only the limit of your storage device!
If you have edited them into a Quicktime Format such as ProRes; as long as they are ProRes 422 then they can download the Windows ProRes 422 Decoder for Quicktime here: [
support.apple.com]
For instant answers to more than one hundred common FCP questions, check out the LAFCPUG FAQ Wiki here : [www.lafcpug.org]