I'm going to reiterate something I said earlier, and made quite a point about it. This was a SMELL of burning. How many people in their own house would jump out the window at the first SMELL of burning?
If there was smoke, then yes, get everyone off, right away. But a smell? Please, seriously get a bloody grip. How many electrical items make a burning smell as they burn out? Most of them, and how many are there on an aircraft? If I had an evacuation for everytime there had been a funny smell on an aircraft I'd have lost count.
A lot of you haven't read the report and are making assumptions on the severity of the scenario. The facts for those who can't be bothered to read:
The cabin crew and senior SMELL burning.
Captain investigates, starts running cxlist to isolate the cause.
The smell in fact starts to decrease.
Cabin crew at rear believe it's getting worse, after being asked by the senior (who I'm sure more likely said - can you still smell burning? and it's getting worse yes? - See where this is going - Leading questions)
Senior is at the front, tries quickly to get Flight Decks attention and can't (instead of shouting if necessary - "I'm going to start an evacuation Captain"), so decides to action it herself.
Flash fires don't just start with a smell, if it was that hot there would be smoke, I can't recall one instance of a flash fire that started with just a smell.
Poor communication from all, and an itchy senior made this relatively common and simple problem turn into a mass of paperwork and headaches.
So, go on then, hands up who answered my first point about jumping out of their first floor window after smelling their toaster burning the bread? Chimps.