Yes, experts talking ********, like being down the pub with a bunch of boring old farts....Until a few more details emerge, this thread is just mostly full of speculation.
The landy might be aimed at the central reservation, but will not hit it from the near side lane in anywhere near 0.4s. 60mph is 27m/s. 0.4s would be 11m. Straight across, yes, but not when having to change direction, I would think.
Trailer does not appear to have turned over. It should have applied its brakes on becoming detached from the towing vehicle. The load should be secured adequately - I would expect the load to tip over the trailer rather than come adrift. I’ll wait to see some more details, if the truth is ever realised. We might know what should not have happened, but not what did occur, or why.