Never proved...but the circumstantial evidence is pretty strong. Harmon's agent was the infamous Norby Walters. Norby Walters was connected with the mob, in particular, the Vegas mob. From the August 3rd, 1987 Sports Illustrated article called "AGENTS OF TURMOIL":
.....as well as the Bills' second-year running back, Ronnie Harmon, who has admitted receiving $54,172.92 from Walters beginning in his junior year at Iowa. "That's not so much money," Harmon told SI. "That's over two years. What's that, $27,000 a year? I had living expenses—an apartment and a car."
From the same article: Big 10 and Southeastern Conference representatives checked into the possibility that some players involved with Walters might have attempted to shave points in football and basketball games. Harmon fumbled four times in the first half and dropped a pass in the end zone in Iowa's 45-28 loss to UCLA in the 1986 Rose Bowl. Conference officials say they have found no evidence of point shaving.
Also from the same article: Yet not all the money went to feed the poor, hungry relatives: Harmon's $54,000 debt reportedly includes a $25,000 down payment that Walters and Bloom made for him on a leased Mercedes.
The fact that Harmon was on Walter's payroll is well documented. Walters connection with Vegas bookmakers is also well known. There is way too much smoke for there to be no fire. Harmon's quotes to investigators later showed he had no morals and a large appetite for fast money. The Rose Bowl was Harmon's last game and there was a lot of betting action in Vegas, and lots of money to be made. Watch the game replays on Youtube with an open mind and draw your own conclusions.