Nice video - it certainly covers all the bases that could cause a sticky shifter. I just had that happen to my MDX ('04) in the middle of a long road trip last week. I suspected that the problem was just the metal-to-metal contact between the eyelet on the end of the cable and the post on the end of the lever on the transmission. I just shot some lube onto the end of the cable, ran the shifter back and forth a few times and it's shifting like it always did. Apparently the normally reliable Honda engineers used some inappropriate dissimilar metals for the connection, and corrosion builds up in between the two surfaces.
If it happens again, it will take me as long to get the can of spray lube I carry out of the headrest storage compartment as it will to fix it (I didn't even pull the fender liners out of the way, but just peeked around them and used a 4" nozzle on my lube spray to direct the flow to the offending parts). If it happens when I'm near my garage, I'll probably pull the cable off and really clean and grease the interface.
The video will take you through "doing it right" though, and will cover a host of other things that could be the problem, though from what I've seen and read, the eyelet and post are by far the most likely problem with a sticky shifter in your MDX.