Falsifying a logbook can be career ending for a pilot. At an absolute minimum you can expect 1 year off from the FAA.
Charlotte also does not have enough mechanics to send them to aircraft for fake delays. The line mechanics are swamped. It’s likely once maintenance posted the estimated ready time a decision was made to accommodate the late connecting passengers. That would be a proper decision. Could the delay have been extended a few minutes to get them onboard? It’s possible.