Hard to fathom how the 5 Oh hasnt recommended a prosecution here.
It's probably down to the chances of actually securing a prosecution.
I suspect it hinges on this, from the article:
"Gurpreet, himself, 'may just have been accepting that which [Digwa] told him', judge William Mousley KC later said, but he added that he was 'sure' Mr Nowak never said or did anything racist. "
And another bit from the article may support that hypothesis:
"Officers later placed the siblings together in a police van, where their conversations were covertly recorded.
Speaking in Punjabi, Vickrum admitted to stabbing Nowak multiple times, including in the chest. "
If they can't prove he deliberately and wilfully lied to the police, then they're not likely to secure a conviction. From the detail in that article, it looks like it may have been justified to send a case to the CPS, but it's impossible to be certain without more detail, which it looks like the Daily Mail and the KC they're talking to, don't have.