At first glance I would have thought the redness to be caused by the same chemical reaction that causes the smokering, but the question is how would smoke penetrate deeply and randomly into the meat.
A second thought would be some type of enhancement process whereby a salt-containing solution was injected into the meat, but if this was a packer in cryovac from Walmart, I don't see that being the case-- the packers at Walmart today were Excel by Cargill, USDA Choice.
Another thought was salt in the rub being embedded in the meat by handling or turning with a meat fork. I did a Google image search on brisket to see if I could find something similar looking, but to no avail.
I think if anybody's seen this before and has a clue, it would most likely be Jim Minion-- or maybe this guy here in town who has "Brisket King" emblazoned on the back window of his pickup truck.