Your right I could have sworn they beat Indiana twice that year. Of the 5 losses that year I remember the OSU loss and obviously the UNLV one. I thought maybe there was a fluke loss to NW or something mixed in there. I checked it you are right.
If I remember correctly, we lost to OSU, @Michigan, @Indiana, Purdue, and UNLV.
The OSU loss was a crusher, too. #1 in the country, undefeated, everyone feeling good, then we lost at home. I remember watching that game at my grandparent's house and couldn't believe we lost. I was only 9-10 years old at the time and didn't realize there was no such thing as an unbeatable team.
Speaking of UNLV, that 1990-91 team that lost to Duke was the best college team I've ever witnessed in my lifetime. Even though they didn't win it all, they were better than the championship team from the year before.
There were a couple of other Duke teams that came close to that level IMO (the 1992 repeat title team, and the 1999 team that lost to Uconn).