I think this will be the case. This was also the case in the PSG match played in Paris, and Dortmund passed the elimination thanks to the posts. PSG had too many balls returning from the post. If something similar happens for Real Madrid, why shouldn't Dortmund beat them? Borussia Dortmund is strong enough to play at the top level. I'm sure Terzic will manage to adapt his students in the best possible way. Also, as a coach, I am sure that he will take charge of bigger teams in the coming years.
Sometimes bad luck is one of the factors that causes a team to fail to win, and that happened to Paris Saint Germain in the semifinals when they felt that every time they got a chance, their chance ended up hitting the goal post. In the end, Borussia Dortmund managed to win and advance to the Champions League final.
Things like this are things we can never predict and the same thing could happen to Real Madrid, where their chances have to be countered by the goal post for example.
When that happens, it will really affect the players' mentality, because when they continuously experience failure when attacking, it will make them frustrated. One way to prevent them from getting frustrated is to have a strong mentality. In fact, Real Madrid already has that mentality and maybe that will be their weapon in this match. We don't need to doubt the mentality that Real Madrid has, because they are the team that has it.