I can see it from both sides.
If you are rushing a member of your family or a friend to hospital I don't really think it would cross the average person's mind how they park when they pull to the A&E.
At the same time you still need to be considerate to others and the extra 10 seconds it takes to park relatively straight, or at least leaving the car next to you with access to it's door - unless having a heart attack or something - is very unlikely to cause any long-term problems (trust me, I am a Doctor on another forum).
Now moving on from this I see a lot of people who are almost condoning violent act towards other people's cars - kicking them, keying them, damage which costs £hundreds to repair.
I've had my car keyed. I was parked on my Mums driveway in a nice area. Let me tell you, it's not nice, and the £450 (and that's mates rates, would have cost me around £750 at a regular bodyshop) and 3 days without my car that it cost me, was not fun either.
No-one has the right to damage anyone elses property. If you feel that strongly about someone's parking - wait it out and confront the person, or leave a note with a contact number. By damaging someone elses car you are in my eyes, worse than the person who's parked inconsiderately. It's unlikely when parking they have purposefully gone out of the way to make your life hard. By vandalising someone's car you are KNOWINGLY, and without any care or respect
whatsoever, damaging someone's car costing them HUNDREDS or possibly more. When in 99% of cases all they've done is cause you 5 minutes of inconvenience.
Also as a general note why do people quote pictures?