Having had to deal with the Japanese medical system recently I can say
simply that from a cost perspective it has the US system beat to hell.
 The total cost for delivery of our son with an epi and the doctor
having to come in at 2am when my wife decided to go into labor was ~US
$4000.  The birth of our first son cost us over US $14000 in the US. 
The second birth had 5 days and 4 nights of hospitol care and baby
care.  The first had 3 days and 2 nights - and the hospitol stay cost
more then the whole 2nd birth, baby care was extra and not included in
the $14000.  I know the costs because my wonderful company decided to
tell us 'oh don't get the national health plan, we have great
insurance!' that only covers 80% of anything they decide is reasonable
after a $250 deductable - and will not pay the hospitol directly.

As far as 'tracking' every needle - how?  Should they take a video of
where they put every needle?  Should they use a digital camera?  What
if they make a mistake and take the wrong needle out then think
they've got them all?  They take every reasonable precaution.  Maybe
you would have liked it if your friend died on the table while they
looked for the needle?

Mistakes happen and sometimes they are just that, mistakes.  The
wonderful US sentiment that 'someone must be responsible' is just
assinine.  I love the parks and playgrounds around my home - my kid
loves them too.  You'd never see them in the US because the
city/county/etc. should have 'known someone would get hurt' and would
have been sued to death the first kid who fell down and broke a bone. 
Seems like a simplification but it directly shows the difference in
legal system and mindset.

I do agree though that he and his family should have been notified
immediatly of the situation though.  And have they done an x-ray to
find the needle and determine if it needs to come out?  Also I do wish
him the best in his recovery.