I agree that she wouldn't get in his truck...was responding to the possibility as to whether it would still be "aggravated kidnapping" if she had. But I think he hit her on purpose and then grabbed her before she could get up, even if she was able. I don't think he would even have needed a gun.
I just think a gun would explain why it was so clean. If someone knocked you off your bike then came up with a gun and said in that tone cops often use get in the truck or I'll blow your head off most people would quietly obey because you wouldn't have a chance to think but you could be right.