If there are sell orders below that range, the margin orders won't execute at all, so you get a negative spread.
So in the current situation we have about $1500 being called at 290 BTS/USD. However since there is about $5000 USD in sell orders below the call price of 284 BTS/USD the call doesn't execute because they are still sufficiently collateralized against the actual market price (~280 BTS/USD) regardless of the feed.
Is it that the dex market price trumps the feed price when deciding when to execute a call? Am I close? If that's the case then the rule makes sense but the display is a bit...confusing.