Same problem here. Although not only related to M4 but anything you hold in your hands. Not good when you are low on ammo already and then waste it to that glitch.

Yes, confirmed.

This happened to me when changing channel on teamspeak and then trying to return to the game, is really annoying when you are looting silently in a city.

Confirmed issue, this happens in ArmA 2 as well, somehow the click for bringing the game up from your taskbar gets passed into the game.

Workaround: use alt+tab to get back into the game.

Confirmed, this happens with melee weapons, too. My character will start swinging constantly, until I click the LMB a couple of times.

Related to any kind of weapon, even melee.

This is a major problem, I agree. I've killed multiple teammates from this glitch.

Hi everyone,
we looked into this and it has been scheduled for a fix. I am unable to give you a time estimate at the moment, please be patient.
Thank you all for your feedback!
Regards,
Andy

This has been fixed internally and should be fixed on Steam soon.