Hunter was more interested in forging his career on the big screen, rather than television. However, I've seen several sources say that his wife was the one who was the aggressive deal maker and essentially demanded too much for his return to do the 2nd pilot. Some speculate this was an intentional move, so that he wouldn't be locked into a TV series contract and instead have the freedom to do movies. Why not decline simply because you're not interested? You then have to deal with the bartering to try convincing the producers otherwise. By making an unreasonable financial demand, it short circuited the process <-- that's my speculation.