The original intent was supposed to be that Adams and others would not be on TV at all. The TV broadcasters relatively quickly realised that there was a loophole which meant that as long as his voice wasn't broadcast they were within the rules. But what was weird was that the UK government didn't immediately close this loophole (especially given that the same loophole was not available in the Republic of Ireland where the same broadcast ban existed at the time).

Small nitpick: I don't think it's right to refer to him as "Gerry Adams MP", due to the policy he followed of refusing to swear the oath of allegiance and thus not taking up the seat.

The problem with the nitpick is it inevitably runs into the issue of who the authority is here, and, by the very nature of the beast, said authority is disputed here. It seems small, but in reality it’s the whole thing.