Is the fact wizards give guns to the whole station at once metashielded?

I had a run in during one of my games that had a mid-round wizard. I was playing security and the wizard gave everyone on the station a gun, I watched guns appear in both my hand, and a few other crew members hands. My character would now be aware of a gun appearing in my hand, as well as other crew members. Now a small conflict happened with the two people that I saw get guns, they both shot each other, so as any security officer would do, I told them to drop the guns, the first one did, and the second said no and ran away. I disabled, detained and took their weapon. I gave them only 3 minutes in a cell because in my opinion, they had no choice they got that gun, So I only charged them for resisting arrest. While I was booking them, the wizard gave the station more guns. I saw this prisoner that I just arrested holding a gun now, they stashed it and when their time ran out I told them to give me the gun before I let them out. They insisted they had no gun on them, insisted I took it when I searched them before. After a long argument and refusing to drop the gun, I stunned and cuffed and took the gun that they had in their pocket. They then went into LOOC and told me, “You should not know I have that gun you are metagaming.” Regardless if that is the case or not, I did see them holding it in the cell. I let them leave after taking the second gun even though I could have put them back in a cell for that, but I did not want to push it further because this person seemed already very upset.

So my question is, if I did not see them holding a gun in the cell, would the wizard event that gives everyone a gun metashielded? Or does my character know that everyone gets a gun, just like I do?

This happened on Salamander as well, the MRP server.