The colleague called difficult may be the one keeping an inconvenient fact in view.

Reputations for being difficult are often earned by refusing to let something drop. The person who keeps returning to the awkward number, the missing consent, the promise made to a customer, is doing work the room would rather not do, and the discomfort attaches to them rather than to the fact. Labels are cheaper than answers.

Next time you hear someone described that way, ask what they are actually saying and whether anybody has answered it. If the answer is no, that is worth noticing. And if you are the person with the inconvenient fact, keep it short, keep it factual, and keep it on the record.