The Scottish rockers were headlining the British event last month and they have insisted the Nine Inch Nails vocalist was wrong to blast them on Twitter after he had no idea who they were.
In an angry tweet, he had written: ''Should be an unusual show tonight at Reading ... the lying promoter and the band following us (whoever the f**k they are) f***ed us on our production.''
Biffy Clyro front man Simon Neill has responded and suggested Trent struggled with the idea of playing immediately before the prime spot on the bill.
He told Faster Louder magazine: ''He basically spat his dummy out. Nine Inch Nails are a huge band and they've been headlining loads of festivals everywhere and I think their manager or someone told him they weren't headlining Reading and Leeds, God forbid, and he decided to take it out on us.''
The 'Many of Horror' group were also headlining at the event's sister festival in Leeds - which has the same line-up - and Simon suggested Trent was ''just being obnoxious'' with his comments.
He said: ''He played with us on the Friday night and there was no problem.
''He didn't care about the Leeds bands obviously and he knew damn fine who we were, so I think he was just being obnoxious.''
The beautifully shot advert was released on Sunday and has become a significant hit.
The band re-post his video on their social media page.