Do I owe potential collaborators an explanation for late follow-up? I had a meeting with a potential collaborator month ago, and at the meeting I had agreed to email them within a week. However, shortly after I began going through a stressful divorce. I am worried that the potential collaborator may judge me for failing to reach out in a timely manner. Should I give them some form of minimal explanation for the delay?
You would be wise to bring them up to date and apologize for your absence. If you value the collaboration then you don't want the other person to think you just gave up on it. 

The explanation could be minimal or not, depending on your personal relationship to the other person. "Going through a divorce" or "Time consuming personal situation". You judge, but definitely stay in the game. 

Also, if the situation is expected to continue, you can warn the other person that your time, but not your commitment is limited in the short term.