Looking at the statistics of the match, I think it was a match where Borussia Dortmund should be happy with the 1 point they got. They had a very tough match and Bayer Leverkusen wore them out a lot. They are unlucky not to beat because they created a lot of chances. At least they were not defeated, so we have to think like that. Bayern will be the happiest with this loss.
This is not the first match in which Dortmund has acted in this way against a strong opponent, they did something similar in the match against Newcastle. For Dortmund, an away draw is a completely acceptable result, but for Bayer it is a loss of very important points, now Bayern will almost certainly be able to take advantage of these and get ahead of them, although if they win they will be equal on points, but Bayern will have a better goal difference.