If you are shooting when you are walking/running up to a helicopter (to be picked up), it will continue shooting while the helicopter lands and you won't stop until the CGC runs up to the side and watches out for the other teammates as they load onto the helicopter. It is only if you are shooting bullets, however.
When the helicopter is taking off with you in it on the mission (where the U.S. embassy gets bombed and you have to hold off the enemy until reinforcements arrive) it is flying up and you can't see the helicopter's reflection in the building's windows (which are mirror-like).
Throughout the game, when you are riding in the helicopter, sometimes the helicopter's blade's shadow will not be turning on the ground as it actually is.
Throughout the game, the majority of the people talking on the cross-com will just move their mouths up and down when talking - this becomes evident when they are no longer speaking, but their mouths continue moving.