Over the years, it's been discussed quite a bit. I believe, but am not 100% certain that the Citizen Sleuths uncovered it originally about 10 or so years back. ( Carol Abraczinskas).
Basically, there are two camps...coincidence or not a coincidence. I am more in the latter camp.
In addition, recently, I believe it was Olemiss, who found even an older publication that uses the character Dan Cooper in an aviation short story or something. (This one was not Canadian based.)
Now, it's possible that the comic wasn't the main influence, it could have been the older publication....or of course neither.