It's usually said to be the opposite, that difficulty follows price. I think it's more convoluted than that. If price shoots up then more miners are added to compensate. But if price falls then miners will leave. But if too many miners leave then this leaves a lot of unused hardware that someone could scoop up and use to destroy bitcoin by 51% attack. So I think if price falls too much and some miners leave, then remaining miners will want to save bitcoin from attack and will either mine at a loss or stop selling mined coins so low causing price to go back to an equilibrium.

So price can shoot up and difficulty can easily follow to very high numbers. But if price falls enough to cause 50% of miners to turn off then we have a problem. I hope that we wont let that happen which also seems to create a price floor that gradually moves up.