Are you sure? Brian was the lead on the team that stormed the bunker. He’d have at least an APC or (on off days) a Jeep. No way a bike.
He was undercover at the time, working for the OSS, the NKVD, and MI6, MI7, and MI135. The guy had a license to kill, maim, and highly irritate. He didn't even need a parachute, they just pushed him out of the plane.