Yeah, it is actually down to the personality of your BOB. Hire another one and you may well find he does not do it; this was the case with me. Most important thing in this race is to spam pace up / overtake. Also set your spring rate to 18.3 for front and rear and brakes to 0. If you set your brakes at 0, he wont really slow down so long as you keep spamming pace up! You should hit the pace up, just a little bit before the corner.