Good job on fixing this. Tell the kid to bring the bike to you next time it needs maintenance so you can show him how to do it properly.
Although kudos to the kid for trying to DIY and at least he realized something wasn't right.
Sounded to me like it was from the valves. Don't know if this engine is bucket and shim or just tappets, but it seems the oil was not getting there for some reason due to the oil filter being installed incorrectly. I could still hear a bit of that tapping sound in the second video.
As far as working on motorcycles, they are no different than cars, still need spark, air, timing, same oil filter types, same valve actuation types and adjustments, etc.
And just because someone owns a motorcycle doesn't mean they know how to work on them, same as car owners.