hmmm.. this one i'm not quite sure on how to answer you. but i
do have a few guesses. the policemen could be from different
departments/divisions; or they could be from the hospital post but
different shifts, or maybe one of those who you spoke to was an
investigator on call that particular day. It could be lah.
I got another incident where there is this civi driver in a police
car. I was behind it. He suddenly stop in the middle of the road
when there was no other vehicle at all. I had to brake hard unless
my son fell and sustain a cut. I overtook the car and saw the
driver face being very red ( evident of drinking). Next to him was
a girl with heavy makeup. I tried to stop him and he refused. After
several attempts, I gave up. I called 999. That time was about 11
pm in the night. I complained and mentioned too that I am concern
as, if the driver is indeed drunk, accident may happen.
The detective called me in that night at 3 am to ask question like,
are you sure he was drinking and which way did he go... I told the
officer all these in my first call and now they chose in the middle
of the night to call me and disturb my sleep. Then the guy say will
check and revert but never did. I can't remember the guy name and
never got a chance to call him back. It is like, you complain me, I
give you hell kind of feeling came over me ...
you're right, ythe one who called you was an investigator from
traffic police. i think he only called you in the middle of the
night because that's when he's free? cos they are usually on
shifts, and amongst all investigators, they one of the busiest lot.
quite a bit happens on our roads, you see. the one who picked up
your call was an operator; after receiving your call the
information was forwarded to TP. It is highly likely that the
Investigator wasn't around when the info was forwarded, which was
why he had to call you in the dead of the night to find out again
what happened, in detail.
It's a pity you didn't remember his name. try to get his name,
report reference number and contact details the next time smth like
this happens, so you can be updated on any developments in the
case.
No offence la.. these are past incident and I don't
really harbour ill feeling. It's that somehow posted similarity so
I give my account too although nothing good but if the police is
concerned on the nagative feedback, well surely our complains here
will comes in handy, don't you think so. BTW, when I left school, I
actually applied for the police. Was rejected because I wore
glasses ... hmmm so ironic that I am against them now ...

Fret not, no offence is taken at all.
In fact,
I'd rather you do what you did, because what we had was a rather
constructive discussion, don't you think? You listed some examples
from your experiences and I listed my explanations as well. I
believe we both learnt smth from our mini-discussion here. It's
better than just mindless flaming, don't you think? 
And true, negative feedback is good because it helps highlight
certain flaws which might arise when coppers deal with people. I'll
hold my hands up and admit, some aren't terribly good at dealing
with people; I've seen a few. But to be honest, even coppers aren't
exempted from having flaws right? We're all still human, after all.
We all have our own flaws.
But as they say, too much of anything, even a good thing, is bad. I
guess it will apply to complaints too. 
Having said that tough, so long as your complaint is justified,
then all's fine and dandy. It's usually the frivolous and
unjustifiable complaints that rile us the most.
Cheers mate. 