Osmo Design Producer/Project Manager interview questions

Scheduled call via email, Spoke on the phone with hiring manager, onsite meeting with 4 people, waited almost 3 weeks for a response on the last step, allegedly just pending to schedule last step of the interview. Almost 3 weeks later somehow they will be moving forward with another candidate. How was my interview with Mark not scheduled in almost 3 weeks but they were now sure to move forward with another candidate?!