True. Opinions can be diverse. But there are numbers, that are facts or lies. When you claim, that 200 people died this year in a car accident within the USA, this is either a fact or a lie. This is not a question of opinion. And the same way a factcheck is not question of party or opinion.
Discussion
Factcheck is totally subjective. For example, does your 200 include people who had a hart attack? Is your statistic from insurance company? Are you government agency looking to prove that roads are safe (thus motivated to lower the number)