Revealing thoughts of other characters

I’m a bit stuck and hoping someone can help me. My novel is in 3rd person limited POV. In this scene I’m having trouble with, my protagonist is on a dirt road in a wooded area at night, spying on the villain.

She waits for his truck to slowly pass her, then she steps out onto the dirt road to take a video of his truck leaving the scene. At that moment, he slows to go over a pot hole and his brake lights shine on her. She panics and dives into the brush on the side of the road. She doesn’t know if he saw her but thinks he might have. He gets out of his truck and walks back to where she had been standing.

Now, as the writer, I know that he didn’t actually see her. He thinks he might have seen “something” in his rearview mirror but isn’t sure, and he’s going to walk out there and take a look around. He stands there a minute, sees and hears nothing unusual, and goes back to his truck and drives away.

My writers group didn’t buy that he would just leave again after catching sight of her in his mirror. They didn’t know my intention was that he really DIDN’T see her. Any thoughts as to how to indicate his thoughts/perspective without violating 3rd person limited POV? The only trick I’ve used in the past is showing another character’s thoughts through dialogue, but in this scene there are only the two characters and they ain’t talkin’!