^^^^^ All correct. However........
1) If this recording was a hoax or "re-enactment" of a call nobody can locate, there is no "conspiracy", or.......
2) If an officer responded and found no evidence of anything, the incident disappears into the nexus of millions of such calls throughout the PNW over a decade or so, even if filed in a box in storage, or........
3) Any number of other such scenarios where nobody (especially a law enforcement agency) cares about the call and recording, and........
4) Would scoff ("cover up") if a "bigfoot researcher" showed up with a FOIA demand which would require lots of valuable resources to research and find, and which wouldn't really prove anything even if found.
Personally, I find the recording and story very entertaining, but ultimately, like so much other bigfoot evidence, is essentially worthless for anything other than entertainment. No need for s "conspiracy" if government is wise enough to think likewise.