I'm sure his long association with his friend Randy Cummingham, the hundreds of thousands of dollars he's accepted from defense industries and his record on military contracts is just a coincidence.
..I will be looking forward to your presentation of any actual evidence of wrongdoing...
As for his friendship with Cunningham, they were both Vietnam vets and they were both San Diego congressmen, so I can understand why he would be friends with him because on the surface they had much in common.
All defense companies give political contributions to candidates that they think are promoting military spending. All candidates take contributions from companies and lobbyists. Duncan Hunter is strong on the military and promotes military spending so I don't find it in the least bit odd that a defense company would make large contributions to his campaign. I'm sure this was not the only defense company that contributed to Hunter.
Since this was probably not the only defense company that contributed to Hunter's campaign, you would have to know the other companies that contributed in order to deduce anything about his voting record. Hunter could have genuinely thought that one company was better equipped to handle a contract than another. In defense spending you don't always want to just go with the cheapest bid. It's possible that Cunningham helped sway his opinion, but that doesn't implicitly make Hunter involved in any scandal that Cunningham was involved in.