I have seen this justification in some form everywhere. It is essentially a quantifying justification in some form, which tends to say that there are far more cruel regimes citing millions of deaths( like the Nazis or the Japs or Stalin's regimefor e.g) than how the British have been. So, in that sense, the British seem fair and good enough.
Well, if the British were so very benevolent, why would frequent uprisings happen in most of their colonies ( not just India) and why would the people need to be repressed down by force, i wonder? The revolutionaries would then be hung , simply for being nationalistic and wanting to free their country, although, it is not to be considered hypocritical why that logic is counter applied when they encourage partisan activity using the SOE during the 2nd world war. The 1857 rebellion was instigated merely by the contemptuous attitude of the British towards Indian custom, or worse, a purposeful religious divide amongst the people. If what General Dyer did at Jallian Wala Bagh was not murder, what was it then?
What about the ruthless gunning down of tribals folk in Africa? Was that not murder?
Most of the Western historians cite the Atlantic Charter as being the symbol of democracy and the original charter itself states that its aim is that all countries should have their right to choose their own government. However, how many books that mention the charter as an example tell the second part of the story, that Churchill backtracked and said that it is not applicable to Britain's colonies? So, does this mean that only countries under German hegemony have a right to freedom and not the people of Britain's colonies?
I can debate on each of your view points, but in the end, nothing tends to change the hypocrisy and double standards, we victims of colonization have gone through.
I had a similar discussion a year back on a subject similar to this in the discussion of the Boer war crimes, but it just keeps getting repetitive over and over again, and tends to deviate away from the original topic. So, i shall stop with this.