I used to worry about this and being able to differentiate the difference between what is an invalid FC signal and what is just a normal motion by the
PR with regards to blocking the sun or telling his teammates to get away. Now and for the past couple of years, if I have any question whatsoever, I'm killing it. End of story.
The
PR knows the rule (or should) and I'm going to enforce it as such.
To add to this, I also make talking to the PRs during the pre-game warmups. I ask them to show me a valid FC signal and then remind them that if they're blocking the sun, their hand needs to be touching their helmet above the face mask with an elbow locked, and if they're telling their guys to get away from the ball, then it needs to be at or below their waist.
Haven't had any problems or questions since...