Joaquin Phoenix : Turned down split?

Just heard he turned down split, if true that was a big mistake on his part but I think James McAvoy did great job, so it worked out best for the audience imo.

I thought James McAvoy was fantastic and had great fun with his roles. However, I don't think the film itself was as good as McAvoy's performances in it. The film was a bit bland when he wasn't on screen. I think Shyamalan has still to recapture any semblance of the filmmaker he promised to be earlier on in his career.