Poverty and school discipline (with a puzzle)

The Kentucky Center for School Safety has just released its Ninth Annual Safe Schools Data Project, including disaggregation of which students face disciplinary actions for major infractions that violate board policy and even more severe actions that violate state law. Looking at participation in the federal lunch program, here's the pattern:

A first point is clear: students from low-income families face major disciplinary actions far out of proportion to their share of the population. That's important to know, and important to try to change.

A second point is puzzling: the proportions are much further out of whack for board violations than for the more severe law violations. What's that about?

The full report, with detailed analysis and an appendix with data for each school district, is available here.