I kind of know the feeling when they start believing something and won't let it go. Whatever you say now will be seen in the light of what they think they know. If you ask for a second opinion that is justified, could be seen as "trust issues", paranoia and whatnot.

I'd advice you to think carefully before you speak, but at the same time don't delay answers because they might see that as suspicious as well. So try to figure out ahead what is going to be said so you have good replies.

Would you say what got you into care in the first place?