C7000 total fan failure - You won't beleive why!

[PDP-Fan]

Got a call from a customer with a C7000 system. He says that the whole upper row of fans has shut down... no lights... no air movement.
We first tried to re-seat the fans, OA etc. then reboot the OA but nothing changed. So we changed the entire midplane. Problem solved.

But I was curious and wanted to know what caused that failure. Are there fuses on the midplane...? So I started to disassemble the midplane assy and found this (see picture). It is unbelievable but this large power connector was disconnected!

It was just hanging there on it's wires.
I assume (since all the other options were unrealistic) that the person at HP who assembled this did not connect it properly. There is no other explanation because this connector does not jump out by itself (vibration etc.) it really holds tight when istalled right.

I wonder if someone else has ever experienced such a problem??

PS: I made a video about disassembling the C7000 midplane: https://www.youtube.com/watch?v=SLXlkaJrzCs