I think both of you might've messed up a little here...
First, did your friend give you any excuse for not being available till late Sunday night before his Monday AM departure from Chicago? That's so weird, IMO. If he'd told you ahead of time he would be super busy with funeral activities and could only get together late that Sunday night, it would've been understandable, but he didn't. Which...hmmm. That was a misstep on his part, IMO.
BUT...it's entirely possible this urgent medical test was something beyond his control. And I've known people who wound up spending the entire day at the hospital for a single test due to scheduling issues, waiting for results, etc.
AND...I think it was maybe a bit unnecessary to text "At least you finally apologized. I'm trying to give grace because I don't think you would have done this on purpose. Honestly, the reason you gave me doesn't feel like the whole story. Tests don't take an entire day, so I dunno what to think.". You're entitled to feeling like the whole thing was suspicious but the "at least you finally apologized" and "I'm trying to give grace" sounds a bit harsh to me, even if the two of you are bffs, and I can understand his not responding.
HOWEVER...saying "can we just reschedule?" like all you're doing is driving a couple hours to his house and crashing in his spare bedroom is...kind of dumb. No. No you can't just "reschedule", and I'd be especially annoyed since he knew this was a birthday trip.
I have to disagree with your other buddy that "it's a given" your FL friend should reimburse you for the $60 flight credit. Although your FL friend has been wanting you to visit, you were the one who ultimately decided on when. Although...since he was the reason you had to cancel, it would be polite of him to at least offer to cover the $60, as long as he can afford to do so. I don't know...I personally wouldn't expect anyone to refund me if a trip fell through but I can understand wanting your friend to do so.
I'm sad your friend hasn't kept you more updated about his health. This is a 32 year friendship, not a casual acquaintance, and most friends who've been friends that long tell each other when they're going through something. Since it's been such a long friendship and FL friend isn't normally flaky, I'm inclined to say give him that grace and let it go...but maybe not plan any more trips unless he wants to foot the bill.
I hope at some point you hear more from FL friend and get more details because IA...something's missing here. And I'm sorry your birthday trip fell through.
