I can't say former Brewers, since the first one was broken my Damian Miller before he came to Milwaukee, but a small graphic in yesterday's Journal-Sentinel that showed some of the details of Bush's three no-hitters-into-the-eighth-inning and all three were broken up by guys who'd donned Brewers blue in the last few years.
July 20, 2004 (while pitching with Toronto) vs. Oakland broken up by Damian Miller
June 19, 2008 vs Toronto broken up by Lyle Overbay
April 23, 2009 vs. Philadelphia broken up by Matt Stairs