... says he has set out to disprove the big bang (general relativity). Does not say the theory is disproven. That would be newsworthy ... if General Relativity equations are modified.
The way to disprove the Big Bang Theory is to replace it with another theory that answers the cause and effect the Big Bang Theory addresses.
All renowned scientists will tell us the exact state of the Universe within parts of a nanosecond "after" the Big Bang. However, not even one of them will tell us the state of the Universe just before the Big Bang.
Most important would be a theory that explained the uncaused first cause. Until that time, I will accept the Big Bang Theory as God’s method for universe creation. In simpler terms, God just snapped his finger and billions of years of creation began.