Personally, I think that is kind of open to some meta. Now, I can understand if you are one room over on a crowded street, and shooting at someone in an adjacent "room" on the streets. It might make sense for someone to see you and what you are shooting with.
However, does this still make sense if you are shooting out of a window or a roof at an elevated position with no ambience and out of a persons natural line of sight? It just seems like things such as taking care to provide hidden Sniper fire or covering fire falls by the wayside here because even if you are disguised with a silencer taking a suprise shot from the roof top people still act like they saw you and the firearm you had before you lined up the shot then booked it.
I am personally a fan of the old message you recieved of just getting shot or shot at..