Generally, donations in the hundreds of thousands will be enough to have the Chancellor, President, etc. steer the admissions folks to rubber stamp the donor's kid(s). The only reason they wouldn't is if the kid was just significantly unqualified.
These kids must have been exactly that, because the parents felt the need to spend that kind of money illegally, instead. They clearly knew their kids couldn't possibly get in, even with $400K in legitimate donations.