Continuity mistake: When Riggs is following the villains' pickup truck, they make a left turn into a highway and a Delta plane is spotted landing. In the next shot, definitely showing the same turn (note the billboard in the background for "CBS FM" which is in the same place, etc.) the plane changes into an American Airlines plane - note the disappearance of the "Delta" logo and word at the front, and that the Delta plane has a single thin red line, whereas the AA plane has a blue, white, and red stripe along it. (01:28:12)
Visible crew/equipment: As the motorbike falls from the highway, just after it explodes there's a very short wide shot of the site with Danny Glover standing by his car and a couple of guys in hard hats standing around (or running for their life). If you look right behind Danny Glover you can see two people, one in a white hat, one in a red, and one of them is holding a camera - they start moving backwards just before the end of the shot. We then see the bike blowing up, then a close up shot of Danny Glover, from the camera we've just seen. (01:30:25)
Answer: She didn't want him to see that she was a fan of those comical idiots. She was supposed to be a tough nonsense internal affairs officer. She was in fact his soulmate, exactly like him, wild and crazy.