Is Mumbai the rudest city of the world?

I am watching news channels which are saying that Readers Digest has announced Mumbai as the rudest city of the world. Shocking, isn’t it.
One more shock, Delhi was not included; all those Indians who watch Indian news know about the safety of women in Delhi, the road rages. Anyways, I have no offense to Delhi, as it’s also one of the most active cities of India and I also like this place because of good friends. Well, the government is in maximum fault, which cant manage the law and order.
Lets , go back to the survey. The survey was done on three parameters:
I am picking the following lines directly from Readers Digest website:
We sent out undercover reporters—half of them men, half women—from Reader’s Digest editions in 35 countries to assess the citizens of their biggest cities. (In Canada, we tested the people of our two largest population centers, Toronto and Montreal.) In each location we conducted three tests:
• We walked into public buildings 20 times behind people to see if they would hold the door open for us.
• We bought small items from 20 stores and recorded whether the sales assistants said thank you.
• We dropped a folder full of papers in 20 busy locations to see if anyone would help pick them up.
To allow us to compare cities, we awarded one point for each positive outcome and nothing for a negative one, giving each city a maximum score of 60. We did not attempt a strict scientific survey; it was the world’s biggest real-life test of common courtesy, with more than 2,000 tests of actual behavior.
So, which city emerged as the most polite and which as the rudest? Here’s what we discovered:
The Top Three: New York, Zurich, Toronto
Their views about Mumbai:
Last in our rankings was Mumbai, where courtesy in stores was particularly lacking. When our female reporter bought a pair of plastic hair clips at a convenience store, sales assistant Shivlal Kumavat turned his back on her as soon as she had paid. Asked why, the 31-year-old was unapologetic. “Madam, I am not an educated guy. I hand goods over to the customers, and that’s it.”
In a government-run supermarket, a young female employee lied that she hadn’t seen what had happened when asked why she didn’t help our reporter pick up his papers. Another worker stepped on them. “That’s nothing,” said the store’s security guard. “In Mumbai, they’ll step over a person who has fallen in the street.”
Courtesy : readers digest
Now few suggestions to Readers Digest:
Before taking the survey, understand the cultural context.
Are these the most critical parameters for defining the rudest city?
Don’t they need to take the factors like crime etc. in context?
It takes time to understand a city; one cannot understand a city, until he/she lives in that city for some time. They should have considered participatory survey.I hope they know it.

Anyways, I don’t belong to Mumbai, but stayed there, traveled in heavy rush in locals, fell on stations during my initial traveling in locals, it’s an expensive city.
But, then also I feel it’s the most accepting city in world. It’s a very fast city, so people generally don’t look back, but is it rude. I don’t think so.
Mumbaikars have come together during crisis, such as heavy rainfall last year, bomb blasts. Does Readers digest take all these into account?
I think they should have done their homework properly before doing the survey.