When Riggs & Murtaugh visit Kevin Flynn in his apartment, Riggs takes one of the knives out of Flynn's dartboard, leaving two. When the fight starts we can see all 3 knives in the dartboard.
As the stalker is targeting Brad outside of the courthouse and preparing to push him into oncoming traffic, you can see the stoplights changing to yellow and the oncoming traffic stopping at the intersection Brad is about to cross. Not only is the truck that was about to run Brad over not among the stopped vehicles, the stoplight has changed again immediately to green as soon as Brad falls into the roadway in the next shot with the oncoming truck in view.
When Riggs and Maureen are at their dinner and holding hands while she's explaining her plan for the stalker, between shots she goes from resting her cheek on her hand, to the hand by her side, and back to resting it on her cheek.