I just spoke with a friend of mine, who happens to be a lawyer, about this particular situation. I also showed him the design in question. He, without so much as blinking, stated the NFL/Chicago Bears would without a doubt have grounds for a trademark infringement lawsuit. He stated that the orange wishbone "C" is, and has been, part of the Bears uniform since 1974 (prior to that it was white). He also stated that adding the "jersey style" numbers on the back only serve to show that the logo is in fact related to the Bears, otherwise why have "sports" style numbers on the back with the organization's name where a players name would appear (above the numbers)?
He did like the shirt. And I tried to remember his response the best I could. My wording is not exact in his responses, but the purpose behind it is. There's no guarantee the Bears or the NFL would notice or care about the design/logo on this shirt. That being said, if they did then they might have ground to win a lawsuit. Even if they didn't...they have far more money and would destroy CR financially with lawsuits (legal/court costs) alone.