I'm very happy to read that the lab tech was reprimanded.

In all honestly though, it's possible that the physics head is right--not that there was no point in him doing anything, or that it was up to you to just ignore it, but that it might be impossible to change the lab tech.

Did you mean send the essay to the physics head, or the lab tech? If it's the former, that's very brave of you, but I'd be concerned that you'd get in trouble for it, subtly or otherwise.