Homeowner's responsibility for damage done by contractor

In march 2008, I contracted (verbally) with a person to replace the siding on my home. I also told him that I would let him rebuild my back fence after the siding job was complete. Without my knowledge and while I was out of town, he brought in extra workers and started rebuilding the fence. I had not had time to check for underground utilities in the area. While rebuilding the fence, the workers cut the underground tv cable, owned by Comcast. I called Comcast, and they came out and repaired the cable, and nothing more was said. The person doing the work never finished the job, and I eventually hired someone else to finish it. In November, 2008, after repeated calls to Comcast to come out and re-attach my tv cable to my house, I called them and canceled my service. I told them I was canceling because of poor service, and that the service had been less than desirable since they had changed from Time Warner Cable. A few days later, and eight months after the cable damage, I received a bill for the cable repair. The bill is for $1017.28. Am I legally responsible for this damage? I can be reached at this email address during the day, or at [email protected] at night. Thanks. Bobby Kennedy Daytime Phone: 713-213-1777