That's all correct; a long tail of consequences.

Going in the opposite historical direction is the other side of that ledger. The actual plant in question was shut down in 1957. The AEC stepped in years earlier to triage the operation, after actually establishing formal exposure limits in 1950, which didn't exist prior to that point. Before that, the company itself had hired staff to control waste and detect contamination. They had to build their own survey equipment because there were no commercial tools available. The worst of the actual contamination was actually incurred prior to that; 1942-1945, when the gloves were entirely off building bombs.

The lessons have been learned. It's tragic and shameful history, but not terribly relevant to modern practice in nuclear power.