That's a brilliant moment. Often these things are shown later in the programme, with a "we caught this reaction off camera, haha, what do you think" remark, which for me makes it a bit snide and cringy. In this instance, McCoist knew he was live, knew he was probably in shot, and didn't give a monkeys.
Overall, what an achievement in getting to the final. I have no doubts they'll win it now, they've been the best team in each tie they've played and, although Frankfurt are to be respected, they shouldn't be feared in the slightest.