Two people can disagree honestly without either person lying.

Different information, different weightings, different experiences of the same event: any of these produce genuine disagreement between two honest people. The assumption that anyone who reaches a different conclusion must be lying or stupid closes off most of what you could have learned from them.

Before assuming bad faith, ask what they know that you do not, or what they are weighting more heavily. Sometimes it turns out to be nothing and the exercise costs a minute. Sometimes it is the whole reason for the gap.