Their research, backup data, and logic looks pretty good.
It makes sense that an earlier collision (but smaller than the original earth -> moon collision) happened to kill the Premian species.
It is Bush's fault that the crater lies on a rift line.
obviously when working with the fossil record in the p-t extinction area I assume there is so little to work with, and dating issues involved, that without a crater anything was speculation but I was always surprised at the number of scientists pretty much dismissing the impact theory for the P-T extinction, of all the extinctions to be doubtful of. 95% is a LOT.
Now that there may be a crater confirmed, how is anyone going to argue that such an impact wouldn't have exactly the P-T mass-extinction-type effect, given what the more accepted chicxulub impact did 65m years ago.