[Anubis]

This sounds to be a pretty rare case. First, to answer your questions of contact with metal: While the power is disconnected from the motherboard, any contact with metal shouldn't cause any issues. Running the board while placed on any non-conductive surface should also be just fine (the wooden table you mentioned). One potential area for short-related errors is if motherboard risers placed in the wrong locations (i.e. not under a screw hole), as these can potentially short out the board upon power-up. For the order in whch to place the components in the case, it really depends on the case and personal preference. Though I usually try to place the power supply first.

Unfortunately there's not enough information to determine the exact cause of the failure, but I'll list a few possibilities starting with the ones you mentioned:

• Static shock is a possibility during assembly, which is why many people use static bands as you mentioned. Usually any issues would show up later in the hardware's life anyway. This seems unlikely, as I have never seen someone shock a board in such a way.
  
• The board could have been damaged during installation or a misplaced riser. Unless you scraped up the board on something or it had a major manufacturing defect, I'd find this unlikely.
  
• The power supply may have failed. It may have worked initially, but when under a heavier load, or under a load for a longer time, something may have gone wrong. There is no way to verify this other than to put a load on it and test its outputs with a meter.
  
• The CPU could have failed. If the CPU fails, the board won't power on. Another possibility for DOA.
  
• Last, but certainly not least, the motherboard itself may have had a defect. This is the first place I would look, as I have seen more DOA motherboards than you can imagine.
  

Anyway, my order of suspicions would be: DOA motherboard, DOA PSU, followed by assembly error. I've never seen any Intel CPU arrive DOA. The only real way to rule out a manufacturing defect would be to have burned-in the hardware for a day, and even that's not completely definitive.

Did the motherboard's on-board power LED light up when you were testing it? If so, did the fans spin-up as well, or did they move at all?