I don't think natosaichek's comment above attempts to explain the paper's observed correlations. Possibilities include that:
1. Examiners who want to get hired in private industry go easy on their future employers' applications. That would explain the linked paper's correlations.
2. Examiners who want to get hired in private industry help create a quagmire of complex procedures that they will then be uniquely qualified to help their employer follow. That also would explain the linked paper's correlations.
3. Examiners who want to get hired in private industry go hard on their future employers' applications. That would not explain the linked paper's result, though it could still be true if some confounding variable (e.g., different approval rates for different fields and types of client, as patentatt speculates) explains the correlation.
People worried about the revolving door are usually thinking (1). I suspect that it's actually (2), since that achieves the same effect in a way that superficially seems less corrupt, and that requires less trust between the revolving-door employer and employee.