Shit yeah! Really glad you had such a reaction to the movie. Though it it worries me; as one of only 6 people to see and enjoy the movie, your enthusiasm is probably indicative of a dangerous mental ailment. Sucks.
Anyway, the scene in question happened much like you said. We originally had an entirely different (though thematically similar) montage sequence written, but in the midst of shooting, the director (Nanette Burstein) decided she wanted to mix it up a bit and apply techniques from her documentary roots. So she took a handheld and a very small crew out with Justin and Drew in various NYC locales and just kind of let them go. Since they were dating at the time (or had dated until then, can't really remember) they had an awesome rapport and their real personalities mirror the characters' so well that they just fell into conversations that fit perfectly within the film. I agree it's a little jarring for a moment, but it's also one of my favorite sequences in the whole movie because it sort of slam-dunked one of the main things I thought was most important with the story: keeping it real.
Again, super stoked you enjoyed and that it meant something to you. These kind of responses to the movie make my giddy to the point that a little pee comes out.