I got no problem with such except that its on TV for free. One can have TV on in a place of business any other time as long as you either get the signal off an antenna or pay for Cable or Sat TV. Why does the NFL get to suddenly change the deal because of a single show?
So they can pound sand as far as I am concerned! If they want to put restrictions on viewing then they should encode the transmission and charge for decoders! Then they have an argument! Other wise they can should shut the hell up!
Listen to the legal warning again. Almost all sports on TV are broadcast for the use of the private home audience.
If you use sporting events to draw people into your business, you are not within the law.
Whether it makes sense for the copyright holders to enforce every trivial infraction is a different question. But don't believe that just because something is on TV for "free" that you have a right to commercial use of it.