I watched the stream and they claimed that the core's engines might knock out the cameras on the Autonomous Spaceport Drone Ship. Then there was a visual disturbance and a smoke filled long pause...
...
I wondered if they lost that engine or not, but then I remembered how amazing the 2 side boosters looked in their synchro landing and forgot all about it.

Tandem Landing & Core Crash on Drone Ship - 1m52s

Yup, looks to me like that thing smashed into the Autonomous Spaceport Drone Ship going quite fast. Fast enough to strobe the camera at about 100 feet.