so...when he was shuffling he set aside a card from the deck then took the deck under the table to shuffle then put the 'burned' card back on top of the deck and dealt it to himself first?
doesnt sound like he's cheating, sounds like he was mocking you. if you let people do stuff lie that when they are shuffling then of course they will 'cheat'.
sounds like he was a cack handed 'cheat' at best. no way he set that royal flush up he is just making himself look cool, in a very misguided way. probably has aspirations to be a magician but lacks the skill or knowledge. does he happen to be a bit shy and socially akward?
in future make sure people all shuffle the same way:
wash them face down. then gather them into 2 halves. cards flat on the table, never cover the top of the deck, riffle shuffle only 2 times, before 'stripping' then riffle again before offering another player to cut.
when dealing keep the deck level and the top uncovered at all times, if you need to put it down then put a chip on top so the top card stays untouched.
Only burn a card when it needs to be done, not before hand as burning a card is a security measure.
plenty of videos and guides for dealers on the web if you need to know what a 'riffle shuffle' or a 'strip' is. could always ask a pro dealer in a casino too, they will show you how.