The problem is Silva spent a lot of rd up against the cage. It is hard to see if all of those punches landed cleanly. Anderson caught quite a few with his hands and rolled some as well.
When Anderson attacked late in the rd he landed a straight left, then the uppercut and straight left combo, then the superman punch right at the end.
If we are going by pure volume, sure Bisping won. If we are going by EFFECTIVE striking, silva's strikes were clearly harder and affected Bisping much more. Even Silva's uppercut and straight were much more significant than anything bispign threw that round.