Here's a twist on canon information for you. An excerpt from an interview with Kevin Dockery.
Is the wandering Warlock officially Bruce Morrow ?
Yes, he is one of a very few that can transport in and out of the future.
Not the only one. So for every move Bruce makes there can be another traveler counteracting that action.
http://home.earthlink.net/~kywess/doc_interv.html