Another possibility is she hit the pipeline while maneuvering to pick up tthe anchor.
Could it be possible they started steaming towards the port before the anchor was fully aweigh?
Is it possible the anchor watch said the anchor was aweigh before it was?
Is it possible they left the anchor kissing the bottom to move the pivot point to the bow and improve maneuverability getting out of the anchorage?
Is it possible that the anchor was temporarily hung-off the bottom (so it could be released in an emergency) and the brake failed?
Pure speculation but I haven’t seen the AIS data when the mostly likely canidate (M/V Rotterdam Express) picks up anchor.