Nicholas Palazzo
Well-Known Member
Because if he had entered Doriath armed, Luthien would be traitor to her nation for not having reported him straigth away.
That is shaky ground at best. Bregor's bow would still trigger that state, and honestly, she would have had to report his presence armed or not.
The main thing is that the loss of the sword demonstrates the *cost* of the trip through Nan Dungortheb.