"Bosch" star Titus Welliver will NOT fly United after watching the video of a doctor getting dragged off one of its jets ... and the reason he's boycotting is the airline's justification for the incident.
Titus, who also starred in 'Transformers' and "Lost," says it doesn't matter if the passenger is a doctor or Joey Bagofdonuts ... there's no excuse for what happened, and it enrages him United reached for one.