This happened to the London interbank lending market during the week of 15 September 2008, when LIBOR jumped to 8% and the banks simply stopped providing loans to each other. The reason? Because they weren't sure the assets their counterparties (other banks) were sitting on were worth anything (resi mortgages) and they didn't want to find themselves an unsecured creditor.
Mortgages during the subprime crisis didn't fall in price so much as they were impossible to price. This made the credit risk of bank borrowers impossible to price. So funding headed for the doors.
Change up the parties a bit and the banks --> offramps, mortgages ---> Bitcoin, and liquidity --> fiat, as in 2008.
There is simply no way that, as Bitcoin goes parabolic, the on/offramps are prepared to handle a change in the weather which results in a huge influx of withdrawals unless their own bank balances rise significantly. My informed supposition is that most such entities should have high-cost liquidity facilities with commercial banks that can step in and address some of that withdrawal demand.
As then, a liquidity shock (availability of dollars) could break the system without needing a precipitous drop in the market price of Bitcoin.