Slightly different IMO .... she was age 20 and clearly a can short of a six pack, the law is different for men and women (in relation to having sex), if a girl is over 13 but under 16 and the man is under 24 then he has a defence in certain circumstances.
Even if it was the same offence, Johnson would be outside of this age anyway in other words he's old enough to know better.
He deserves every hour he spends in prison and the victim should fleece him of every £ he's got, particularly the £3 million he supposedly earnt after Sunderland knew what he'd done (debatable who actually knew at Sunderland !)