I think they had already blown the budget for the episode. Feathers, especially moveable ones, require a lot more processing, if you don't already have the templates and code to handle them.

Luckily, if Apple can expand this nifty time travel app they have for the iPhone 5, so that it skips back more than one day, we might have a solution for that.

Even if the dinosaurs were mostly wiped out by massive oceanic volcanoes going haywire.

@1: Commit sudoku, the evidence still supports the Chicxulub impact as the main cause of the K-T extinction.

The coup de grace if you will, @2, but not necessarily the primary stressor.

@3: Are you referring to the Deccan traps? There's evidence that the gases they emitted stressed the global food web, but the single greatest cause seemed to have been the collapse of autotroph populations everywhere as a result of the particulates ejected by the Chicxulub impact.
Look, I'm still in college, but paleontology is what I'm dedicating my career to. I've studied this a bit more than you have.