Most of that damage appears to be downstream of the cutout (and, indeed, downstream of the meter and Henley) - and presumably must have been caused by a short downstream of that Henley. Was there a cutout fuse and, if so, why didn't it operate before all that damage arose?What can happen when a cut out or the incomer short out. Moving an old incoming cable can result in the insulation crumbling and the cable shorting out.
I agree that moving an old incomer (not that the OP's one looks very old to me) can result in catastrophes - but I can't see how it could result in anything like what is shown in that photo.
Kind Regards, John