Thats pretty bad luck dude ... and your shop sucks ... I can imagin it being policy ...but on the strenth of the fact you only got it last week..and him being a buddy ... you would think they would make an exception ... Good Business sence really ... Shame though .
I see the pic ... looks crazy ...as pointed out .. you was lucky it never popped all over your plants .
I Have To Ask .....you never touched it with your bare hand while screwing it in did you ?...Some say it leaves a grease resedue that can pop the bulbs when hot .... i dunno ... But i allways handle bulbs with a clean cotton or silk cloth just in case
Even with the coolshade ... DON'T mist near it ,It only takes a tiny gap in it to suck moisture in and poof !... That tube with even just a tiny gap will act like a vacum and hoover the moist air in .
Besides ....As far as im aware ... its better to mist when lights are off as the water droplets act as tiny magifing glasses and burn leaves under intence light ... worth thinking about and im sure people here with more experience than me will back me up on this .
Ether way dude ...Good Luck and i hope it works out for ya
BTW ...i ended up getting the " PowerPlant Super HPS 600w " after seeing your horror story ...it made me paranoid .... But at the same time i do understand it could just be the luck of the draw ...or a schoolboy error !