About 40 years ago when it was built. They have been operating from that pad for decades - you trying to read stuff into it that isnt there is ridiculous.
I'm referring to the day of the accident but I think you know that. As far as reading stuff into it, two helicopters collided because one departed a helipad at 90 degrees to one landing on another helipad! Clearly there was a fatal flaw in operating that way so the ridiculous idea is that it had nothing to do with the outcome.