During the opening, when the game warden is looking inside the beaver dam and is attacked, he is not using the regulator. During the attack scene when the game warden is being dragged across the lake, the regulator is in his mouth again and you can clearly hear him screaming.
When Keough and Cyr are arguing in the boat and Wells asks if he'd please drop the anchor. As he's asking, the boat is moving rather quickly, but when Keough tosses the anchor over, the water is still indicating the boat is stopped.
When Wells shoots the tranquilizer into the trapped croc you can see the pink-feathered tranq projectile. The second croc jumps, is shot, and we cut back to the first croc who no longer has the tranquilizer dart.
When the four main characters first canoe down the lake, an above shot shows the four properly rowing by holding the oars by the tops of the handles. In the following closeup, Kelly is holding the oars differently.
The shadow of a camera on a tripod is briefly visible on the torso of Jack's shirt when he's talking to Kelly about US Wildlife. This is right before they look up at Hank dangling from the spring trap.