If not already said...

1 - Lose the bolt croppers

If the tools to break a lockoff are removed it reduces their options.


2 - Electrician uses their padlock which must NOT be a safety type

Thereby being more difficult to simply break open with a screwdriver.
Safety padlocks are often weak so a lost key doesn't mean broken (&
live) equipment.


3 - Electrician should wear 00 or 0 safey gloves and assume live
working

Plenty ways to become a conductor across L-N without an imbalance
tripping an RCD.


4 - Most difficult - do the Directors know (as they risk criminal
charges)

Directors can only control that which they know - both re policy &
enforcement.
Your difficulty is finding out - any admin staff aware of the problem
as they can actually be useful at casual contact & dropping a comment
"cutting the lockout nearly killed someone today". Realise it need not
*just* be the electrician that is killed, realise it is perfectly
possible for it to be a whole group of people if metalwork becomes
live.


The problems suggest a deeper *political* problem re management and
perhaps certain personnel re intimidation, blackmail, whatever. So
tread lightly. No matter what, an electrician must be confident a
locked-off circuit will remain so. Indeed their electrical body CAN
involve H&S. Perhaps the best route is to get someone else purely as a
H&S reporter whilst keeping the existing electrician whose life is
probably not that great if he is willing to put up with this.