And as the article stated, the uniform they brought was not approved for that game so they clearly knew it was the incorrect uniform.
Did you read it properly? They asked to wear a special jersey but were denied due to a colour clash. They were told they had to wear their home jerseys but “missed it” in the discussion about the special jersey, and ended up bringing their away jerseys because they were the away team.
I don’t think they knew it was incorrect. Sounds to me like its just a (fairly silly) mistake. I wouldn’t expect any team to take two uniforms “just in case” either.