These comments are actually libellous.
Not really, he has just said that bike doesn't look like it belongs in that house and that the person may have a friend who works in Halfords.
They are statements of belief, you have read that statement as he has a mate who works in halfords who is stealing stuff for him to sell for profit
. Its you who has mentally inferred some thing that could possibly referred to as libellous.
Even the title says 'possibly nicked
', not this bike is stolen
. He has just applied a belief he has based on the evidence presented. He hasn't purposefully presented a lie as a fact. In the same line a murder suspect who is arrested and charged with murder but acquitted can't sue the police for libel because they believed the evidence showed that he was the guilty party.
Libel also requires a proof of lost or damage due to the statement, again, there's not much evidence of that as he got £780 for it, not a bad return on a £1000 bike!