This, from the Guardian article on the case sheds more light on the matter:
The pair were said to have taken a taxi back to Makele’s flat in Hackney where they had sex and the woman stayed the night. The next day she went to the police and alleged that Makele had raped her and prevented her from leaving his flat. She said she only managed to escape after he fell asleep.
Makele consistently denied the charge and said sex with the woman had been consensual. The CPS subsequently told Makele’s solicitor, Paris Theodorou, of the London law firm Hodge Jones & Allen, that apart from text messages showing contact between the two after the event there was nothing else of interest on the phone that needed to be disclosed.
When the phone was eventually returned to Makele, Theodorou commissioned an independent download of the phone’s contents and discovered more than a dozen photographs showing the pair apparently cuddling in bed together.
They undermined the prosecution’s version of events, suggesting that the relationship appeared to be consensual. Theodorou then served the CPS with the images that had been missed.
In court a barrister for the CPS said the prosecution was also being dropped because of another issue that had raised doubts about the credibility of the complainant.
However, what is reported here doesn't rule out the possibilty of a consensual encounter that turned non-consensual. The photos in themselves prove nothing. It's perfectly possible she went to bed with him consensually, took pics, then he turned aggressive, raped her and wouldn't let her leave.
I don't know what the other 'issue' was that also undermined the credibility of the complainant - it could be something serious, but equally it could have been inconsistencies, alcohol consumption, mental health problems, prior rape complaint etc.