My husband is a Genral Contractor and completed a remodling job in November 2008. A painting sub contractor that we used on just that job has just sent us an invoice for his work from Sept. 8 thru October 1st 2008. We had no idea about this invoice until today (7/29/09). This invoice is for work done 10-11 months ago and he\'s just now billing us! Are we liable for this bill? My husband will not ask his customer to pay the bill as this would make him look horrible!