Or, more specifically, can they be wrong without being considered false prophets.
For example, I don’t agree with the practise of cutting intermediate hymns short during General Conference because speakers took up more than their alloted times. Not only do I not agree with it, I think it’s wrong. Does that mean I think they fail as prophets, that they are false prophets?
I don’t think so.
Arguably, my example is an administrative issue, and has nothing to do with a prophet’s prophet-ness. But perhaps there are issues that have everything to do with it.
I am sure many could come up with a quote or two from earlier church leaders that seem anomalistic to current Church dogma. Do one or two (or even a handful of) quotes that seem wrong mean their owners are false prophets? Do such few quotes negate dozens or hundreds of accurate quotes?