You're absolutely right about the correlation changes. However, gold's correlation to the general market was developed organically by human behavior over time. That does often change during crisis.

However, options contracts are a form of derivatives, meaning they are contracts financially engineered to hold a specific correlation. So, you can build perfect hedges using options contracts, which is what they were originally invented for. People just started betting on the markets with them, which created all kinds of risks in the market.