Hi,
AdHoc reporting is just the name we gave to this method of reporting. At the time, there were already two types of reporting: v13 reports, in which you have to validate, schedule, ping for status and finally download the report, and the v200xxx reporting where you have to first define and then download a report. We chose AdHoc to convey that it is done on-the-fly as opposed to the other methods. We didn't mean to imply that it is related to the site you linked.
- Kevin Winter
AdWords API Team