When participating in any race where both competitive and recreational athletes are involved, both types of athletes must be aware of their actions.
She should have been very aware that he also runs races for different reasons than hers and when people compete, mostly it is against themselves, they push their limits and get lost at the end of the race in their focus to better themselves and finish strong.
Recreational runners tend to think everyone is out there to have fun and smile throughout the whole race because it is fun. I understand the waving and wanting to high five or embrace the family,but they also must take into consideration the fact that other athletes are out there on the course hoping they have a perfect day.
As a competitive athlete, I too have been cut off by recreational runners and I have tried my best to avoid them but also I have run into or shoved a few out of my way. I keep my eyes on these runners, but when they seem to be set and not moving and I commit to running right by them, but not always do they know I am coming and quickly shift directions and I must react appropriately to keep from falling.
If you say you are at fault, sh!t, then you are at fault for crossing to the opposite side of your route, or backing into a running with the right of way (runner finishing or on the correct side of the course) and take full blame without expecting an apology.
If you believe he saw you and you tried to avoid him also, then maybe it is expected for both to apologize to each other. But, we still have no video of exactly what happened.
For now, as you said, you are at fault and that should be the end. If I impede an athlete for any reason and I get run over, sh!t, I got run over and I blame myself and hope te other person did not get hurt.