David,
The XL2 does not literally record 24 progressive frames per second to tape, it records a 24p signal onto tape over a standard NTSC 29.97fps interlaced signal. This gives the look of 24p when played back, but the footage is not truly native 24p.
3:2 pulldown is the term used to describe how a 24fps signal is recorded on 29.97i. Three whole frames are recorded, followed by two frames that are split between two fields. If W=whole and S=split, the pattern (also called a cadence) is WWWSSWWWSSWWWSS, etc. If you record a movie off of an NTSC broadcast, then step through it frame by frame, you will see this same cadence. Read this link for details:
https://www.adamwilt.com/24p/index.html#24pRecording
The Canon XL2 does not have an Advanced Pulldown mode like the Panasonic cameras. Therefore, Final Cut Pro cannot automatically remove the 3:2 pulldown when capturing footage. You must use Cinema Tools in order to do that with 24p non-Advanced footage.