Schapiro dropped the money market crackdown when it became clear three of the five SEC commissioners would vote against it. Among the commissioners who opposed it: Democrat Luis Aguilar, who previously worked on Wall Street at money management firm Invesco, which the report said personally lobbied Aguilar to oppose the plan.
Aguilar agreed, issuing a lengthy statement on August 23 saying, "I remain concerned that the Chairman's proposal will be a catalyst for investors moving significant dollars from the regulated, transparent money market fund market into the dark, opaque, unregulated market."
Invesco had expressed similar concerns a few months earlier, warning the SEC in a January 2012 letter that the proposed reforms risk "triggering a sudden, widespread shift of assets to less regulated vehicles that do not offer the protections" afforded by SEC rules.
Responding to POGO, SEC spokesman John Nester discounted the influence of the alleged revolving door in the matter.
"I imagine you could find alumni on all sides of this issue," Nester told researchers.
Former SEC Director of Enforcement Robert Khuzami goes further, calling the revolving door a "myth."
In an opinion piece for Reuters in August, Khuzami wrote that enforcement decisions are made my "teams of attorneys with multiple levels of review and scrutiny throughout the agency."
"Enforcement staff, having landed a highly sought-after and difficult-to-obtain job, often passing up other opportunities in the process, would not risk reputation and career and even jail by undermining an investigation for a possible future job prospect," Khuzami wrote. "(T)o put it bluntly, would you hire someone so dishonest, so without principle and held in low esteem by former colleagues … to represent you in matters of importance?"
(Read More: SEC Enforcement Chief Khuzami Departs.)
Khuzami, a former General Counsel at Deutsche Bank before joining the SEC in 2009, left the agency on Friday and plans to return to the private sector.
—By CNBC's Scott Cohn; Follow him on Twitter: @ScottCohnCNBC