Seems silly, but make sure he connected the OTA antenna into the correct input! There have been several reports where it was incorrectly connected to the UHF antenna input for the remote control! In that case the remote will likely still work (from short range anyway) and the stronger UHF channels might still find their way to the tuner.
I also have the 622. This model reportedly has a superior OTA tuner vs. other receivers, but IMO it is not as good as the tuner in my TV, and only about comparable to that in the 811 it replaced. Also, the OTA tuner in the 622 is digital only. I know you said your UHF channels are HD, but to be sure the 622 won't receive any analog signals as the earlier tuners did, just FYI.
Welcome, BTW...