The incident reportedly happened October 2 at the TG Beruas Anchorage near Malacca. The dredge in the video is believed to be the Oceanline 5001. It’s unclear what caused the dredge to slam into the tanker at about full steam.
The tanker has been identified as the MT Strovolos, registered in the Bahamas. It obviously suffered a fair amount of damage in the incident. Both vessels were separated a few hours afterwards.
I suspect there was no officer of the watch on duty aboard the dredger - or, if there was, he wasn't doing his job - and the helmsman was either asleep or completely distracted. See the result for yourself.