Oh my god the ammount of illiterate people reading this chapter is astonishing, I don't like the way the MC decided to go about things as much as the next guy but I can at least understand why he did it which he literally explains I this very chapter
(HE DID TO HOLD ON TO THE VERY WEAPON HE HOLDS THE MOST TRUST IN, HIS FUTURE KNOWLEDGE OF THE GAME, WHICH WOULD BECOME USELESS IF HE CHANGED THE PLOT THIS EARLY ON)
Sorry about the all caps it was just so frustrating seeing so many comment mad at what the MC did(reasonable) AND also wondering why he did it(unreasonable)
Except he's caused a number of changes already which are going to send things off the rails anyway.
For one, Riela is in the room and is extremely dedicated to the MC; and from her and other's perspective some rando baron's daughter just up and attacked a duke's son. Since MC didn't tell her anything about his plan, It would be completely weird if she didn't do something.