It really isn't. They certainly have more insight into their subjective mental state than you, so basically you're just saying 'coincidence?!' about an unmeasurable phenomenon where the observer has qualia and you do not.

It'd be like if you said 'I had an idea yesterday...' and I responded with 'Did you though? Maybe you just overheard it and thought it was yours! Maybe you just thought of it now and incorrectly associated it with something you did yesterday!' It doesn't add any extra information while dismissing your own conscious experience completely.