yup!  The thing he left out was checking the limit screws on the derailleur.
after disengaging the cable with knuckle trick pedal the bike and the chain will jump into the small sprocket 
once again with the knuckle trick push the derailleur into the next cog and let go if the H limit screw is correct the chain will step lightly into high gear if not we to adjust 
next push into lo the low end and similarly use the second to top step for examining the L limit adjustment  (he alluded to this hat end of his cable dressing).
There is also the derailleur hanger that can be easily bent in a crash or just falling over while parked.  Symptoms of a bent derailleur are the chain going past the low gear cog and falling into the space between that largest cog and the spokes.
There are tools for adjusting the hanger that involve removing the wheel and derailleur. in keeping with the "quick and dirty" theme of the video using an allen wrench as a lever, place the wrench in the derailleur mounting screw head (5 or 6 mm depending on the age of the derailleur, use the one that fits) apply a bending force to the hanger while standing directly behind the bike so as to see that the derailleur cage and pulleys are coplanar with the cassette/freewheel.  At this time we can also see any misalignment in the fore and aft plane.  THe same twisting lever action will remedy these noisy and poor shifting conditions.  In all the axle, derailleur mounting screw, and jockey wheel bolts need to be parallel.  I looked on youtube for a video of these descriptions of derailleur hanger alignment and didn't find one.