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.
IMO, it shouldn't be as specific as you say. Even though based on statistics and data, Leverkusen is much better than Dortmund. The problem is, Dortmund's position is not in a stable condition. in fact, Fullkrug had several chances besides one assist in the match. The conditions experienced by Edin Terzic's squad are not in a pleasant position. some of the pure stickers they have are not able to perform well in every match.
Before the match against Leverkusen, Dortmund exhausted their energy to overthrow Milan. It would be very natural if Edin Terzic's squad played two tough matches at the same time in the near future. This affects their performance. but it cannot be denied, the fact is that Dormund took the lead in the first half. If only, Edin Terzic's squad could survive until the final whistle sounded. meaning, Leverkusen fell at the BayArena, their own headquarters. Luckily for Xabi Alonso's squad, in the 79th minute Okoh Boniface was able to equalize and avoid defeat. and as a result both teams must be willing to share points, and the one who benefits most from the results of this match is Bayern Munich.