Factual error: When the hitman shoots the Mustang's windshield, the damage is not consistent with a shotgun blast at close range. The windscreen is actually hit in two separated areas. Winchester would be very unhappy if their guns really shot like this.
Factual error: After the mid-point chase scene, Lt Bullitt drives to an airport hotel identified as the "Thunderbolt hotel in San Mateo." The hotel [originally 'Thunderbird' in the early '60s, renamed 'Thunderbolt', then 'Clarion', finally 'Aloft' in 2012.] is located adj the SFO runways at 401 E.Millbrae Av Millbrae, not San Mateo.