In the Season 7 clip, at about the 0:13-second mark, Robin reveals to the group that Barney is “one-quarter Canadian” and sticks a little Canadian flag in his suit’s breast pocket. He, predictably, freaks out immediately, saying, “No. That’s not true. It’s impossible!” and gets up to run out the door. Only, he forgets to throw the flag on the ground, so he comes back in to do that. And then the door won’t close, so he’s stuck acting ridiculously upset while trying to unlock the door to close it. To top it off, he’s wearing the infamous, yet adorable ducky tie.
The cast and crew roar with laughter in the background of the scene, watching Neil Patrick Harris struggle with the door all while staying in his distraught character. Then, someone off-screen quips, “That proves he’s a Canadian,” earning some delighted laughs from the cast. The actual scene plays out similarly, though he only storms out of the door once, throwing his flag on the floor before leaving.
Barney shines in his moments of extreme dramatics, and this blooper highlights that to a tee.