Phineas could have been working under such a system and have had to tender for the work, recruit his gang, and pay their wages out of what the contractor allowed. The 'shrewd, smart business man' may have referred to how well he worked within that system. As an aside, when the early railroads actually began transporting passengers and freight, they also operated under a sub-contracting system. Sub-contracting was also quite common in New England factories until almost the end of the nineteenth century. What was the weather like in Cavendish on 13th.
Many diaries record that it was cool or even cold in Vermont and New York on that day.
But I have not found a weather record for Cavendish itself. We know from its reprinting in the Boston Post that the first account to be written for a newspaper was that for for the Ludlow Free Soil Union . I very much want to see the original but only a single copy of that newspaper seems to have survived in the whole of the United States, and it is for 9th. We also know he commenced work for Jonathan Currier in Hanover, NH, early in 1851. But no one seems to have recorded seeing him in between.