There has to be more details that were not revealed. Was there a problem at the motor, possibly. We don't know how close this motor was to the victims, what kind of grounded objects were in close proximity to the water, as well as within reach of victims or other details. To be electrocuted you have to come in contact between two different points of potential or current is not going to flow through you. The water may have been energized, but so would the shore around it, although depending on conditions there could be a relatively short distance between significant potential levels - that is a possible place for something to happen, or if there were a metal sign or fence post near the edge of water it could easily be at a different potential than the water but maybe reachable from the water - you would have to touch both at same time of course.
It is a terrible accident but, media reports sometimes are just not accurate enough when trying to explain the cause of such events because they really have no clue how electricity works, or if an expert tells them one thing they report it as they understand it even if they changed it enough that other experts look at it and wonder what is going on with that.