Basically. To give one example (and this one fucking guy was basically responsible for 90% of the fuckups of the forerunners) the Master Builder Faber, that is to say the head of the Builder caste, which at the time held political supremacy in the Forerunner Ecumene - this was also the guy who designed the Halos, so he also fits the HMRC brand in that he came up with a weapons idea that does this:
Hey, you know that weapon that assaults the physical concept of the grander living universe so badly it seemingly withdraws all thought from the volume of space affected?
He made a killing during the Forerunner-Flood war by rescuing ships that had been in combat and fixing them up, then reselling them at a higher price. Of course since he was a lazy fucker, he didn't have the ships inspected thoroughly enough so the dormant Flood on the ship always came back, infested the crew working there, and started fucking everything up.
He kept the Flood war a secret from the majority of the Ecumene for 300 years before it clusterfucked so wildly it started overrunning the galaxy.
At one point he
dumped the effective military commander of the entire Ecumene in an area the Flood had occupied to the point that FTL travel no longer worked, essentially giving them perfect access to all their plans, as a political move. No way he wasn't HMRC material.