I could not find any referring explictly to Ozzy back in the day.
As far as I remember, this is what happened (narration built based on comments from contacts close to the Maiden camp). You should be able to find reviews from Black Sabbath fans at
www.black-sabbath.com
First show: Maiden went down a storm and stole the show. Bruce said on stage that Maiden were not one of those bands that just kept doing reunions without putting out any new albums.
Second show: Maiden experience some sound problems, with no PA on the first song. The Maiden camp suspect their sound has been sabotaged (no pun intended) after being better received than the headline band.
At some point during the tour, Bruce criticises reality TV.
Final show: Iron Maiden get their show severely disrupted. According to a photographer working at that event, after the show there is some shouting backstage (Steve not being pleased with Bruce). I asked a photographer who used to be very close to the band and who was present that day whether there was any truth in those reports, and his response was that he could not possibly comment on that.
The rest, as they say, is history (of Iron Maiden).