yougotcheated%. If you're reporting that accurately, I'm calculating one in 8 billion chance that the dealer has 21 aces up, and pulls a blackjack on each one, in 100 hands.
1. Is this game handheld? If so, watch the dealer's eyes the whole time they are dealing. A mechanic (someone cheating with their deal) will peak down somehow, either to look at the top card, or look at a marking on the top card. If he's not dealing seconds (dealing the second card off the deck), he may be holding out a ten card; hiding it up his sleeve, or somewhere on his clothes. Watch his hands while he's dealing. Does he scratch, or do his hands leave the table?
2. If it's in a shoe, watch the dealer's eyes again. If he's using a gaffed shoe, there will be a mirror he needs to look at, or he'll need to look at marked cards. Is there a brush on the shoe? Many gaffed shoes also require the they face the players directly, instead of being at a 45 degree angle from the dealer.
3. Is the dealer always flipping over the same card? Some dealers will do a selective flip, for example always turning over a ten so that players will bust, instead of standing when the dealer has a stiff. It doesn't sound like he could be using this method, but who knows.
I don't see any way he could be stacking the deck, because he doesn't know how many cards will be out there. The only way he could be doing this is with an "anchor" at third base taking cards for him, so the cards align for him to get a blackjack. But this would stand out immediately.
Find out who runs the casino, and then find out who handles gaming control in this area. The most likely scenario is that this guy is a solo cheat. Could be the house cheating, though, especially if there's a cheating shoe involved. Oh, and don't play with that dealer ever again.