MotoGP Qatar Race | 2018

I heard it was a K&N oil filter that failed and sprayed oil on the brakes.
The team was notified about potential issues, along with seeing many many opinions posted on Facebook trackday groups... but during lunch someone from the Suzuki team told Ducati that recalls are just for legal mumbo jumbo and can probably just be ignored. They're now pursuing a lawsuit for damages and the fate of international prototype motorcycle racing is in danger.