There have been many attacks in Greece where people got surrounded like that and ended up in hospital, not for being nationalists but for looking like nationalists. And there was no help from the police and certainly no sympathy from the court. In one case, an antifa group attacked someone with a shovel right infront of the police who pretended that nothing happened, and when the victim was taken to the hospital the police went there and arrested him with charges of being a racist. The metro network is a place where often such attacks take place, despite the abundance of CCTV, so the Spanish guy probably preferred to save his life.