Well how about:

Back is too rounded at address
Stands too far away from the ball at address
Left knee collapses at the top of the back swing
Over swings the back swing
Right foot stays planted on impact rather than rising
Hips do not rotate so that the arms and wrists are used to flip the hands through impact

Apart from that it's fine!

Actually he reminds me of a friend of mine who was a real powerhouse but only used his arms to swing and lost so much distance.

If you want this guy to take lessons, I'd appeal to his ego and tell him that if he did he'd add on another 50 to 80 yards on his drives.

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Cleveland Launcher 460 - Aldila NV 65 x-stiff
Callaway Big Bertha 3W - Aldila NV 75 x-stiff
TaylorMade Rescue Dual TP (16°, 19°) stiff
Mizuno MP-32 2-PW Rifle Flighted 6.0
Titleist Vokey Wedges 52°, 56°, 60°
Scotty Cameron Circa 62 #3 35/330