"You can't just stop a marathon if you're tired... I can't stress how bad this (tournament) has been supervised or looked at by the medical team here in the whole tour," Cash told BBC’s Radio 5 Live in the aftermath of Federer's 6-4 3-6 6-1 3-6 6-3 victory over Nadal. "It's wrong, wrong and wrong... It's cheating and it's being allowed. It's legal cheating but it's still not right," added Cash.