Auditors find rampant problems in highway construction inspections
Construction inspection services contracts were often missing several critical pieces of information that could be used to ensure the state was getting its money’s worth. Auditors found that contracts had no scopes of work – detailed lists of tasks that must be done under the contract.
Depth, width, length...that's it! Inspectors do the paper work and the company gets paid.
And we're not even considering that forms come in set heights! 
So if it wasn't the right form height then the wrong forms were deliberately used to make the contractor more money.
And if they used a slipform paver then they had to know the specific depth to even set the machine up to lay the road! 
Corruption, collusion and fraud, all the way, IMO.