Not sure it was a penalty or a red but Armstrong was superb and scares the life out of defenders.
You got it spot on northwesthoop. Originally I thought it was a stone wall penalty, however, I've now watched the game again and in retrospect it was a very soft decision.
It shows just how difficult the officials job is because my initial thought was that the Cardiff defender deliberately strong armed Armstrong. However, watching the replays from different angles not only wasn't it a penalty but the defender never deserved to be sent off.
When I checked the slow-motion playback it looked as if the third defender pushed Armstrong as he went into the penalty - onto the path of the two intervening defenders. If so, that was ironic that a foul outside the box was converted into an unintended foul within....