Selma Payne's POV:
After thinking about it, I thought the most likely reason was that Sir Evaria was wrong.
He didn't lie to me. On the contrary, he told me everything he knew, but he didn't expect that what he knew was fake.
In other words, the Evarian responsible for caring for the dead man had deceived Sir Evaria.
This was not hard to understand. That group of people had even cooperated with the demons. Deceiving their family head was child's play compared to this. Sir Evaria's silence was not only a form of indulgence but also a warning. He did not agree with his people plotting against the throne.
Of course, those people could not trust him with his ambiguous attitude, so it was reasonable to hide some things from Sir Evaria.