If it wasn't Labour who hired ATOS, you would have a point..
It is not really relevant to what he was saying though. Rightly or wrongly, Labour will not get blamed for this kind of thing because the Conservatives are currently in power and have not shied away from the punitive measures against the poor/people receiving social security which ATOS is emblematic for.
My predictions:
I really struggle to see the Conservative vote growing. I tend to think the Tory vote has less range but a higher base level than the Labour vote. Given how badly the Tories did at the last election when Labour ran a dogshit campaign, were a mess in no fit shape to govern and were three-times incumbents; I can't see any massive growth there.
The Lib Dems will lose a lot of votes but not so many seats. I've said it before but they tend to be quite resilient on a local level (another reason why polling is not a great measure). They've lost any sympathy voting, that is for sure. But perhaps that never really served them particularly well anyway?
Labour.... it is difficult to see their vote growing on their own merits. I hope they offer something 'radical', if only for differentiation's sake. I think their vote will grow simply because the more social-liberal/student vote will shift towards them (and is being/will be courted by them), while the SDP Liberal Democrats will not shift towards the Tories. Similarly UKIP will siphon more votes from the Tories than from Labour, not in a particularly meaningful sense, but it will help some.
I'd say we probably end up with a coalition again. I lean towards it being a repeat of the current situation, but only around 55-45. It really, really depends what approach Labour take.