How to confront perceived dishonesty...

Without out right calling someone a liar. Not only do I not want to hurt this person, but I am open to being wrong. I just don't think I am, so friendship can't stay that way unless I can confront it.

I just know my word choices may not land like I would like them to if I am too blunt or direct. Curious how others creatively or gently speak about such things.