Yes, it is traitorous, but in order for it to be traitorous, the person who picks it up should be the only person around it; if it's a group of people where anyone could pick it up, then no.
In addition to this, stating that you have picked up/have a T weapon is also KOSable as "Having traitor weapons (silenced, knife, harpoon, tear gas, etc)" is a traitorous act. So it's best to avoid stating that you have one.
So, I want to add onto this since I have a question relating closely. If you get the secret knife, and say "I have the secret knife." can people then kill you for that? Since you stated you had a traitorous weapon ( a knife. )
What's the use of a secret knife, then? I feel like it will easily be used to kill people within the rules. Example: "Hey guys, I got the secret knife." "RIDDLE HIM WITH BULLETS, HE HAS A TRAITOR WEAPON!" If you're going to die just because you have the secret knife, there isn't much a point to it. Thanks for answering the question though.
You can keep the fact that you have a traitor weapon to yourself rather than disclosing that information and using said traitor weapon later into the round to your advantage.
Is stating that you have a Traitor Weapon KOSable under any circumstances? Like if a Detective states that PLAYERA is proven, but PLAYERA states he has an MP7, can I still kill PLAYERA? Also: does it show up in the logs when someone has a Traitor weapon, even if they picked it up?
If you acknowledge that Player A is proven and know it to be true (a detective isn't a tester) then continue to kill him, you are held responsible and can be slain. If Player A is carrying traitor equipment and you know nothing about their "prove-status", you can still kill Player A. But if a detective says someone is proven, I would take their word. Both of these scenarios are followed by someone saying "I have (traitor equipment here)".
It's not the players' job to know who is proven and who isn't Holding a T weapon is KOSable either way, whether you know or not, as there may be other reasons behind the player being "proven" I usually don't kill for people saying they have T weapons, or say they will drop it for the Detective, etc. unless I'm a T However, like stating you are a T is KOSable, it's only right that stating you have a T weapon is KOSable as well As an example, when in Murder, the logical thing to do is not say you have the gun, because the Murderer will most likely target the one thing that can kill him
Also, another question, if you say you've committed a T act -- killed an inno, destroyed a HS, threw a grenade (even out of harms way) -- can you still be KOSed for that? Whether or not anyone saw it happen and it doesn't affect anyone, besides, of course, the person you killed.
If you admit to doing a Traitorous act you can be killed for it. You do not need to be seen doing it.