It has already been said by others, but that was an exceptionally sloppy execution, especially so for someone executed for the danger of possessing a resurrection skill. But then again, if the kingdom had been appropriately thorough, the story would be over, so it can't be helped if the author wanted to keep things simple. If things didn't need to be this awfully one-sided, there could have been a third party subtly intervening, leaving the kingdom still in the belief Licht is dead, yet not make the execution look as half-assed as this. However, that might not have turned Licht vengeful enough since someone would have actually helped him.