I am not sure about civil cases but in criminal he doesn't have to prove anything does he? I thought as a defendant he had to be proven guilty?
"Proof" can mean a lot of things .... and different things in different cases.
In this case , we have 40+ women all making the same accusations , then you have text messages between the accusers and Watson substantiating these accusations.
Most of you don't realize this but the crux of this case comes down to the definition of "Consent". Watson's definition Vs that established by law.
Bottom line , Consent cannot be given / extracted under duress nor in instances where the victim is mentally incapable.