Is this dumb that i never snitched?

Inna simple version, this kid ill call him Bob (easy to write) takes his nail and goes on the back of peoples neck and slices the neck, not wide open just a little small cut. What i didnt know is he went from nails to metal like the metal on pencils.

He got caught and i guess the security guard was calling people into the hallway cuz during lunch im called, he ask me what happened and i said idk because at the time i didnt know that bob used metal.

Im let back in lunch but saw assistants peaking around me very noticeably.

(This isnt really important)!The next period the security walks in and ask for bob, and i SWEAR i heard my name get called by my teacher or the guard. I go into the hallway and the mf says who tf are you and i never called you as if i didnt see him 20 mins before🤯

Then about 10 mins after i get called to the main office, the ask me to show my neck, a pic, who and when it happened. I said i didnt know who because when it happened they ran off into the crowded hallway. They knew i was lying but told me to go back to class.

I was told by my parents later it was metal and i would be sent to the principals office the next day.

Explanations

I didnt really care about the nail cut, it was funny and harmless

Metal has a higher chance of being infected with some crap so im gonna just say at first it was funny but with metal its not. I mean what can I really get in trouble for? Im closing their “case”