The companies know exactly what they're doing (At the time the NHS contract was awarded I was working for one of the (unsuccesful) consortiums bidding).
Offer a low bid to get the deal, and then stiff the client when you're too far along for them to scrap the whole thing - they have to pay rather than cop the political flak for wasting the money spent so far.
Companies like IBM, Accenture and PwC dont make billions from messing up bids
.
And besides - its irrelevant to craskuk's point - he alleged that a company would employ someone knowing that the employment would cost them money overall.