While people are slowly getting used to appointments coming from the left-field, his hiring as sales director still caused jaws to drop among media agencies, quickly followed by a brisk rubbing of hands as they - and some of Channel 4's commercial rivals - contemplated how they can expect to get one over on him in the negotiation round.
Whether it likes it or not, Channel 4 is more dependent on the spot market than any of its rivals (it has no production division and it owns no content), so getting in the right person to maximise this was crucial.
And given that Channel 4 has lost its ratings bankers Big Brother, Glee and Friends, it is likely to be a particularly tough trading period if, as expected, audiences start to go backwards. The appointment of Allan from OMD, then, seems a particularly bold move by David Abraham - a fact made even more pronounced given how many other "proper" airtime traders there are in the job market.
The critics lined up to say that here is a man who has never sold anything, has been out of the TV buying market for more than a decade and whose only experience of the wider client world are those he dealt with at OMD (interestingly, among these was Channel 4). In short, they've written him off already as a terrible choice.
And yet, and yet ...
his hiring does seem to be another part of the general shift away from the more hardened sales chiefs of old, who pursued negotiation with a blood lust, towards something a little softer and, dare I say, interesting.
Along with Simon Daglish and Kelly Williams at ITV (who at least both have sales backgrounds), Allan represents part of a new generation in commercial television that is more about ideas, partnerships and innovation than sniffing out a weakness and staring out an agency buyer on the opposite side of the table.
They are also more familiar with developments in the digital sphere, which although currently represents just tiny amounts of revenue, may one day grow as content becomes increasingly viewed across multiple platforms in the new connected world. Perhaps.
But I can't help feeling that both ITV and now Channel 4 are expecting this brave new world to arrive sooner than it actually will, and that consensual media trading is a lofty ambition but is just that - an ambition. Whatever - Allan may have to work hard to prove the naysayers wrong.