Perhaps you have to be overly accommodating to sick people, since they're never 100% any day. The bicyclist apparently didn't help himself much, but there may have been extenuating circumstances - he may have lost his light, his smartphone died, had 3 flats, etc - you just didn't hear about it in the short conversation.
Ultimately it comes down to your own conscience, which apparently is troubled or you wouldn't have bothered with the OP. Be nice to the next few guys, and your karma balance sheet should be in the black again.
I can relate to this story a bit. I followed a guy's bike tour from BC to Ushuaia and back through the States. I knew he was headed in my general direction, but since he had no fixed itinerary I didn't try to contact him and offer a place to rest, thinking he would not pass near me. He camped nearly every night, and by chance ended up "stealthing it" in a wooded lot only a couple miles from my location. He was 300 miles further North by the time I learned of the missed opportunity.