The FlyerTalk email has a blurb on this thread that peaked my curiosity:
Extortion by the Wheelchair Pusher?
Walking was slow and painful for fairhsa, who needed a wheelchair to get around while very sick. After being assisted to go from the gate to the taxi stand in Bangkok, the wheelchair pusher demanded a tip and would not stop until the price was acceptable. Is this a form of extortion upon a person who is ill or disabled?
I was imagining the wheelchair attendant continuing to push the wheelchair past it's destination extorting money from the rider. (Picturing grandma screaming and whacking the dude with her bag trying to get him to stop.)
I think my version is far more entertaining.
As for the guy demanding a bigger tip: while I don't think $3(us) is unreasonable, the man was RAF and doesn't belong in the service industry. If there's a next time, tell him there will be an envelope left for him at the desk and hop in the cab asap. Then when you're home mail off a complaint to his manager (hence the envelope.)