A few years back, I was taking a course for my then-job, and the lecturer told us about a group of people in one of the major Australian constuction firms (though he didn't say which one).
The job of these people was to go through all tender documentation looking for things which hadn't been specified properly, or which might conflict with other things in the tender documents. When the construction company bid, it would include a laundry list of conditions of their tender, usually saying abstruse things like "In s.311(a) of the Scope of Works, we have bid assuming that existing conditions on site are foo..." and the like. On those tenders they won as the conditions turned out to be different to what they'd assumed (bearing in mind that these conditions were now part of their contract), they'd be able to ask for a variation (and more money) for most things - pushing up the price of the contract while allowing a competitive bid price. This is all legal, and frankly, not that uncommon.
The interest thing is that this company had actually worked out how much revenue these guys - the contract analysts - brought in, and they found that the revenue per employee for these guys was more than for any other employee in the entire organisation.