If that's what she's saying, they should clearly be asking more questions.
Why should they doubt her? Magic has most definitely played a hand, chaos is already in the streets, and there are no other sources to counter any claims she makes.
It's a time-sensitive, immediate issue, there is limited information but none to contradict her, and what she claims can be plausible.
Any demons bound into templars were already being controlled by Tahrone, so they weren't exactly a shining example of typical demon possession where they just cross over. With Amalia, that particular demon only needs to say a few words to get past an unsuspecting regular person before running out into the world to wreak havoc. As for requests like that... Thrask's daughter Olivia actually made one just like that and still mutated, so even that doesn't seem to count, in addition to those mages who "accepted" Uldred's offer under torture, so I think it has to be an agreement not made under duress. Also, Anders is the one who confirms that abominations have an instant attack reflex if provoked.
...Xil, the entire points of Uldred and Olivia were that they were under duress when they made their deals. Desperation is completely valid grounds for a possession.
Anders is also not a routinely accurate authority on the topic of abominations either.
And I didn't say I'd kill them, I said I'd try them.
In the past you have said you would kill them. Sometimes you've conceeded you would convict them first.
Gaxkang was possessing a corpse and using some sort of magic to look human.
And?