that risk shit was pretty bad! Mustaine has lost his shit a few times now... I bought a bunch of megadeth records from itunes a while back because I have no idea where my original copies are, and they were all mixed entirely differently, with NEW VOCAL TAKES, and other new recordings overdubbed here and there. He went full-on George Lucas on us. Some of those older records, Mustaine would get his hands on the recording budget, spend it on junk and speed and whatever else, pawn the band's gear for more drugs, and then finish the record with whatever broken pieces were left. And you can hear that on recordings like "So Far, So Good, So What."
Have you read the book Mustaine published a year or so ago? He goes into detail about how much he hated that album and other recordings from around that time. I recall him saying he felt physically ill after hearing the finished album, or something to that effect.
If you havn't read it I advise you don't, assuming you're a fan of some of his work. It was interesting, particularly the early history of Megadeth, but I lost a lot of respect for the band and their music after reading it. Without coming right out and saying it he makes it obvious that Megadeth never was about the music and he never gave much of a shit. That's no shocking revelation but hearing it admitted right from Dave kind of sucked.
I still consider Rust in Peace a classic and one of those rare albums which are perfect from start to finish, but it was a fluke.