M4 Buttstock CQB will flash on/off when equipped on the M4, while having the M4 on your back un-equipped, while running when camera is facing characters back.
Only occurs from behind the character with about a 45 degree cone of camera movement from behind.
Flashing will not occur if camera is facing either side of character. Front side, walking, or sprinting not verified.
Additional Attachments Present at time of First Occurence:
M4 Carryhandle Optics (standard)
M4 Handguard Plastic (standard)