I feel your pain. I’ve done both and I know it can be very frustrating trying to get a rec. One thing I’ll add, a rec at a small corporate operation is a heck of a lot different than a rec at an airline with 14,000+ pilots. Not saying you didn’t deserve it, but lots of times if a Corp guy recs someone who doesn’t work out (or quits to go back to the airlines etc) their reputation will be tarnished. In the airline world, recs are a dime a dozen with no real downside for the person writing it.
My 2 cents, if you like the guy, be the bigger man and write them the rec. I’d always rather go through life with one more friend.