Yes, in the Olympics sport of boxing this year, corruption is evident. It just came out that several boxing judges have been dismissed in the wake of corruption allegations. The Olympics are supposed to show their best to the world. Cheating is not something that should exist in the Olympics, and the sport of boxing needs to shape up and clean up after these corruption allegations.
There are certainly a lot of complaints in Rio, and not just by the US. Also, there have been media reports about corruption in amateur boxing with judges and referees being involved in manipulating draws and matches. Without proof, you can't say for sure, but there are plenty of people pointing to corruption.
Corruption is found in every part of the world and always has been. It has become more the norm than anything else and speculation of the possibility cannot be ruled out from any facet of any operation. It has been proven to exist in other boxing events and I see no way to exclude the possibility of corruption when it comes to amateur sports.
Olympic boxing is involved in corruption. This is not a conspiracy theory, but advocated by a high-ranking official. There have been a string of curious decisions to back up this claim. The latest was Vladimir Nikitin beating Michael Conlan and Evgeny Tishchenko decision against Vassiliy Levit. The U.S.A. head coach also believes there may be corruption.