I heard Aldisert say that Gura is running through open doors on outside the home. Minute 6:03. That suggested to me that he thought that the 2A applies outside the home under existing 3d Circuit precedent. I think Hardiman was alluding to the same point, saying that the 2A applies and thus the court gets to step two (intermediate scrutiny). Gura didn't hear that in the question, but I did.
I have only listened to part of the argument. I did hear the same statement with the same implication you did. Aldisert's statement came as Gura was reiterating the fact the 2A applied outside the home. I took the statement as meaning to move along to the application of the standard. As others have noted, it looks like the panel is going to apply an intermediate standard; or, perhaps they'll punt and rule that the law doesn't meet either strict scrutiny or an intermediate standard and the court doesn't have to get bogged down on what standard applies.