Yeah, it usually isn't shown on TV. I remember the Wolves lost a playoff game on the delayed penalty back earlier this decade. They were on the good end of delayed penalty and as soon as the extra attacker went on the ice, they lost control of the puck and the puck found the back of their own net in OT. That was just about as strange of a finish as when Boyle put the puck in the back of his own net in OT. I knew about the extra attacker for quite some time, but that was only thanks to the video games. The announcers only mention it when they have the puck for a sustained amount of time, enabling the 6th attacker to get out there.