Looking at revision history and the timestamps of both examples you provided, one possibility for the reason your edits were rejected was not because you lost an edit race with a 2K user, but you actually lost an edit race with the OP of the questions AND it was within the 5 minute grace period of the edit. The likely order of what happen is something like:
- OP posts his/her question
- You click edit on the question shortly after it was posted
- Shortly after you (or possibly before you), the OP clicks "edit"
- You commit your edit
- Shortly afterward, the OP commits his/her edit. Since it is within the 5 minute grace period, no edit history is captured. It still appears as if the original posting is the most recent revision
This scenerio would also explain the time lapse between your suggested edits, the rejection time, and when the next edit was captured in the revision history
Because the OP has a binding vote on edits for his/her question, your edit is rejected by Community (this is a similar effect as if a 2K user reviewed your edit and tried to improve your edit from within the review queue - when this happens your edit is immediately rejected or accepted by Community). But since it was within the 5 minute grace period after the post was made, there was no indication in the suggest edit as to who edited your question after you.
But in general, Community never provides a reason for the reject. Because it does not have the ability to think for itself (yet), it does not know why it is rejecting the edit.