Adding to the problems associated with the Prudential project, during 1960 and 1961 there was a series of allegations made against Callahan claiming he had been engaging in illegal activities related to his second tenure as Public Works Commissioner. These allegations included charges of financial kickbacks, bid rigging, and other questionable practices. This led to a corruption trial which threw a pall on his reputation that did not help with his drive to construct the Turnpike extension. On top of the legal allegations, a group of three professors from MIT and Harvard made public allegations that the Turnpike Authority had been using inflated numbers to push through its bond issues, thus artificially inflating their values. This led to failed series of bond issues that critics hoped would prevent the Turnpike Authority from raising the needed funds for construction.