I'm also on a Flames board and we have a 100 post thread on this subject.
I was originally told it was an email from the NHL telling them to black it out. I then asked to see the email, then speak to a supervisor. I was hung up on.
After another 30 minutes on hold I got a helpful CSR, and was told it was a Bell screw up. My guess, the Flames game was to be blacked out in Edmonton and they hit the whole area.
I will be contacting Ken King (President of the Flames) about this with the names of people from the Flames board. If anybody would like to add their name, PM me.
Also, if anybody has the name or number of a CSR that told them it was a non-Bell issue, I'd also be greatful for that info as well.