About two-thirds of the most successful Plaintiff's trial lawyers went to non-"Top 25" law schools, while about two-thirds of the most successful corporate lawyers went to "Top 25" schools. This is hardly surprising to anyone familiar with the profession.
Plaintiff's trial lawyers of the type described generally work in small firms that serve the general public. They aren't screened by a corporate hiring committee. Ratings of trial lawyers are generally based on results, which are partially due to marketing to find good cases, partially due to luck, and partially due to solid legal skills.
Corporate lawyers generally work in large firms that serve large corporations. The hiring committee of a corporate law firm uses the best available data to judge incoming associates, which generally consists of law school prestige, law school grades and law review articles. Ratings are generally a function of the kind of clients who hire them and thus, can afford to pay the highest hourly rates. Developing clients can often benefit from the connections that one can develop in elite schools (more undergraduate than law school, to be honest).
The linked TaxProfBlog post speculates that different skills than LSATs and grades are involved in trial work. This is true. But, it is only part of the explanation. Corporate law practice isn't much like law school either. It also ponders the status of tax lawyers. In my experience, tax law and corporate law practice frequently overlap or are even the same thing.
For what it's worth, I suspect that commercial litigators would probably split the difference, but look overall more like corporate lawyers. Criminal defense lawyers and prosecutors probably tend to be more plebian.
I went to a "Top 25" school, and have done both Plaintiff's personal injury work and corporate work while a lawyer in Colorado, although I can't claim to be among the 25 most successful lawyers of either type in the United States. The tenth anniversary of my admission to practice in Colorado is tomorrow. I was admitted to the bar in New York State for about a year and a half before then.