The proper term isn’t scrupulosity, but conscious. The problem these days is that most folks, including young folks, haven’t developed a proper conscience.
Scrupulosity comes into play when you have an unwarranted, unfounded fear that you have sinned, not when you did something that may indeed be sinful.
He seems to think that he did commit a sin of some sort. The question is whether it was mortal or venial. This wouldn’t qualify as scrupulosity.
The safe thing to do is confess it and let his confessor absolve him of it. Then it’s a done deal. Plus, he gets extra graces to help him overcome that temptation the next time.
The late Archbishop Fulton J. Sheen used to say that the worse thing in the world isn’t sin, but the denial of sin. Because if we deny that we have sinned, what need do we have of a Savior?
Perhaps you would enjoy listening to a free talk by Bishop Sheen on the Denial of Sin?