Not quite, prices capped first. Then when that was not enough rolling blackouts where implemented. Those blackouts where excessive and thus reduced the wholesale price below it’s maximum.

As rolling blackouts where implemented by people paying wholesale rates they obviously have an incentive for excessive blackouts. Regulators said, you can only have rolling blackouts while rates are near the maximum because otherwise you’re simply going to keep cutting people’s power off to save yourself money.

Granted, outside of context it seems like really odd behavior. But again this was retroactively filling in periods where prices dropped artificially rather than proactively increasing the prices. It’s no different than the SEC stepping in when someone manipulates a financial market.

PS: That said some of this was simply technical as blackouts aren’t capable of the kind of fine grained second by second control needed to maintain a stable electric grid.