Towards the end of the film, after Snipes beats the crap out of a lot of vampires, Whistler throws Blade's sunglasses to him. They show him throw them in one shot, then in the next shot they show Snipes catching them. But look in the background at Whistler, he doesn't have the glasses, but is moving his arm like he is throwing them. The glasses must have been computer animated, and bad editing contributed to this mistake.
Whenever you see Scud, he's wearing a t-shirt with the logo of the Bureau for Paranormal Research and Defence (B.P.R.D.). The B.P.R.D. is the agency that Hellboy, another comic book character, works for. Hellboy is the next movie to be directed by Guillermo del Toro, Blade II's director.