If you are ingame and got your binoculars/rangefinder/laser designator in hand and you want to switch through the action menu directly to your launcher, the 'put the binoculars down' animation plays indefinitely as long as you do not equip your binoculars or select the primary/secondary weapon again.

Also, if you select the launcher with your binoculars in hand, and hit the fire key, it will break the loop and switch to the launcher, but most definitely will also release a rocket straight up in the air in the course of this process.

You have to switch from binoculars first to you primary/secondary weapon and then to your launcher, which consumes unnecessary time.