After an expensive and stormy legal battle with CBS, ABC finally debuted its The Glass House Monday night. But CBS, which had claimed that the show ripped off the format of its own Big Brother but could not get a federal judge to accept that view, No Doubt took satisfaction with the ratings results. Glass House wound up as the lowest-rated show of the night, save for a rerun episode of CBS's How I Met Your Mother . It drew just 4.19 million viewers in the 10 00 p.m. hour, slightly better than Mother , which attracted 4.13 million in the 8 00 pm. hour. The highest-rated show of the night was again NBC's America's Got Talent, with 11.17 million viewers -- but that figure was down significantly from the comparable night a year ago and was the lowest-rated episode this season.