In Robbie's defence, I think he was deliberately double underlining the point because the two teams occupying the same space/time is going to become such an important and pivotal theme for the episode.

Yes, but there were ways to make us aware they were in the same room that would be a lot less awkward. They could have showed the door with the room number and showed Sam and Dean walking into it and then, later, Rufus and Bobby walking out - they did that through the whole ep anyway.

[Insert here scene with Ninth Doctor yelling "just this once, everybody lives!" and keep fingers crossed this is foreshadowing for the end of the season

Well, it doesn't matter if everybody lives or not - they all come back eventually! :-D (Also, Nine! My favorite doctor! \o/)

Ah, but this ep is referencing Lethal Weapon and the running gag of "I'm too old for this shit"

Oh, you're right! I can't believe I missed that!

Btw, in that gif, is it just me, or does Jensen look like he's wincing because he knows Jared's heavy hand is about to whump down on his head?

LOL! Possibly!