I have a bunch of event attendees who were marked "pending from pay later." Due to issues with their accounting departments we didn't have cheques by the time of the event, but since they are trustworthy partners we allowed them to attend. I updated the participant statuses to "attended" so we could send thank-you letters, but now they are all marked as having paid. This is going to take a lot of manual work to confirm if anyone has yet to pay.
For the immediate concern: is there a way to check for participants with payment type "check" and "check number" blank?
Is there a way to prevent this from happening in the future? Ideally, participant status and contribution status would be independent, especially from the bulk update window, or I could be prompted with a "Would you like to mark the contribution as complete as well?"