Facebook discourse will always be bottom of the barrel. I'd expect there to be a similar post about them being labour fans on some other post.https://fullfact.org/news/labour-party-manifesto-launch-factchecked/
Just glanced through this, seems like some good points and some points that Labour may have exaggerated.
For what it's worth, there were a few posts in the Facebook comments implying Full Fact were bankrolled by a conservative.
Much like the bbc is for Labour and conservatives depending on who you ask.