The band were reportedly bumped from the Capital FM playlist following the snub and issued an official statement about the incident earlier this week.
Talking to James Merritt for BRMB, Tomlinson was asked if Styles intentionally failed to mention Capital FM for a bet.
"No, it wasn't a bet - Radio 1 obviously were a massive influence on [the success of] our record right from the start," he said.
"They had the first play, and I think he was meant to thank both of them and just forgot. Silly boy."
"One Direction forgot to thank the Capital Radio listeners last night when picking up their Brit Award for 'Best British Single'," the band's official statement read yesterday.
"This was an oversight as the boys were caught up in the excitement of winning."
One Direction won the 'Best British Single' prize voted for by Capital Radio listeners and iTunes users for their chart-topping hit 'What Makes You Beautiful'.
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Watch the One Direction 'What Makes You Beautiful' music video below: