How are people casting effects on the King?

[Amaroq]

I just got second place to a Brun who did 2 damage to the King without anyone in the palace. But how is that possible? Whenever I try to cast spells to the King, they won't target him. They only target his guards.

The only thing I can think of is he was stealthed. But I didn't see anyone get revealed or go into a battle sequence. One second, the King was at 2 health, and the next he was dead and Brun won an assassination victory.

[Kletian999]

Casting on king is impossible. But the poppit card, which does 2 damage post battle might explain what you thought you saw