Re: Disney/Marvel & ABC working on Avengers spin-off tv show? - Part 1
Fox were unhappy with his original pilot for Firefly, giving him a weekend to write a new pilot or face the show not being picked up. The original pilot then aired halfway through the series' run despite having a lot of the character background/establishment of relationships in it.
The original pilot for Dollhouse wasn't well received by test audiences/the network, so they shot a whole new pilot, reshot elements of the original pilot hoping to turn it into a regular episode but they couldn't. So it was deleted entirely and elements from it turned up later in the season's run.