Comment by dangrossman

If someone's on the market, they need to apply to multiple positions to make sure they find something in a reasonable time. You should assume anyone interviewing with you is also interviewing elsewhere. Some of those other companies may make offers, and since they interviewed around the same time as you, they're going to come around the same time as yours. "Flaking out at the very last minute" indicates normal job search activity, not a flaky applicant or poaching competitor.