Compiling bits and pieces from different sources…
Special Ops are not constrained by the spending issues for regular military outfits – if there is some exotic technology that allows for a successful outcome, they don’t need to buy 1000 copies.
There are noise canceling technologies (and probably other techniques) that minimize the noise of a helicopter approaching, which is key when surprise is important.
The first helicopter in had to land because of some sort of failure while it was hovering. In order to avoid whatever technology it has from falling into the hands of others, the backup helicopter fired on the first helicopter to destroy it. That was the “bang” the blogger heard.
There are pictures today of the Pakistani military taking the wreckage of the helicopter away on trucks covered by tarps. One sign of where we go from here is whether Pakistan turned the wreckage over right away to the United States or took it somewhere for “research”.
One of the technologies out there is the ability to see heat signatures through walls – to determine if there was actually anyone inside and what room they were in. If nobody was inside, they could have waved off the attack without anyone being the wiser that we knew where he was.