If for engineers it is clear that the different implementation is not the reason for failure, or it is a reason but in very unlikely circumstances, how are the lawyers handled by the engineers in this case ?

The electrician problem, i doubt that any electricians (atleast in the current generation) that know what they are doing would screw up a simple switchstart circuit. In the general case, a schematic can be included on a label inside the device

The failure:
You will have to prove the failure can not be linked to the selected circuit.
The problem is with more likely scenario: When it fails in the way that is more typical for that circuit (lamp "explosion" when the ballast is on Neuttral and e.g. the one who is replacing the lamps touches with one end the grounded sheet metal while the other end is in the socket). That fault would be clearly possible to prevent by choosing the other circuit. That is, what the lawyers will keep pointing out. The fact the other circuit will bring in other problems they will reject as "irrelevant, because that have not happened here".

And for the maintenance errors: The thing is, in many fixtures there is just a bunch of white wires running in one conduit between the lamps, then going to the sockets. So no clear view of the circuit.
On top of that there is a fault somewhere in the circuit (that is, why the electrician is messing with it in the first place). Without being sure how the circuit is supposed to be connected he will be left on just tracing the wires. There he may made an easy mistake by "jumping" from one wire to another (many white wires running along in small space).
You may stick there the schematic, but there is another schematic printed on the ballasts. Who will guarantee the electriocian will really spot the printed paper, when normally that is not required? And what when the paper just detaches and get lost (a common situation with older Elektrosvit fixtures from the 80's, when having the wiring schematic placed inside all electrical things was required by the code)?

I seen a case that describes both the lamp across 230V and the circuit tracing in one incident

At one place where i did network management they built new building, with an area in the entrane lit with 2 x 18W PL luminaires

Electrician installed everything, connects power on. In one luminaire, one lamp goes with a pop and bright flash, other flickers and can't start. I notice this from distance, assume that the luminaire is miswired with 1 lamp on 230V and other in series with 2 ballasts

Come there to see closer. Electrician is looking into luminaire, with the power on. The lamp that made the bright flash have 2 long black "sleeves" in the electrode ends of the tubes, and is doing dim cold discharge like a 40W T12 without starter. Pull this lamp out, something rattling in the base. He put another one in, again pop and bright flash. By this point im at the bottom of the ladder asking to give me a look

Indeed, came miswired from the factory, with 1 lamp on 230V and other on 2 chokes in series..



I dont like the "bunch of White wires" like this, i do prefer them in colors. And i dont like luminaires where the wires see the lamps (UV damage the isolation), so in the good luminaires there isnt any aesthetic disadvantage in using colored wires either

We had here a case where a contradicting schematic is added :

The old 80s Eltam chokes for 150W HPS were intended for use with a specific ignitor from the same company, that needed a tap in the coil near the lamp end. The 80s..mid 90s "K" chokes (older design with open ends of the coil, covered with paper) had the printing on a paper label

Steinitz (used to be big importer of US made luminaires in the 80s) had their own in-house made ignitor, but used Eltam's chokes. So they were ordering the US stuff with no gear, and fitting in the 230V gear. Their ignitor needed the tap near the Phase end of the coil. So they were sticking another label over the Eltam label. No confusion with them, but this 1st confused me when my 1st HPS test circuit i tried to put together with a Steinitz relabeled choke with Eltam's original ignitor, and spotted that the taps are in different positions

Currently Eltam themselfes make 2 different models of ignitor that needs the tap in opposite positions, and they put a big warning label on the ignitor of the type that needs the choke reversed