If you have ever been to Thailand and seen the electrical wiring system there, you would shake your head. 2 wire system with no earthing is very common. You look at the power lines on the posts, and you cannot count the number of cables that are strung there (often tv, telephone transmission cables) but there are cases where electrical lines have been low enough that passers by have been zapped in close proximity. Also, MANY people have been zapped merely walking on sidewalks for improperly earthed street lamps beside them. And many kids have been killed by electrocution in pools, school yards etc. Terribly poor electrical work done there very frequently.
residentially thats not surprising, but for a compound drawing 5MW it requires significant infrastructure in place that is likely free of these flaws, at least for the most part.
and it wouldnt be difficult to install a sufficient grounding system on-site if the power delivery poles did not include a grounding. Drive a few heavy stakes deep into the ground at strategic locations, and wire them all as the grounding system. fairly common