The amount of money that the city paid the consultant over the last year greatly exceeded the cost of the improvements to the mayor's house. The building contractor in charge of the improvements to the mayor 's house had done business with the city in the past. The mayor was aware that many of the bills were being presented to the consultant rather than to the mayor. Authorities are investigating the consultant for taking bribes from officials of other cities.
The mayor has been accused of taking a bribe based on the fact that a consultant that does business with the city paid for improvements to the mayor ' s vacation house. In his own defense, the mayor has said that he paid every bill for those improvements that was presented to him.
Which one of the following, if true, most undermines the mayor 's defense?