That particular answer, which I also just read, strikes me as totally confusing and utterly uninformed. In fact, this is a ridiculous/hilarious statement.
The data is there: that is the data they generate the jpeg from, and then subsequently generate the histogram of the jpeg from.
So you have
-> data (let's be generous and say 16-bit values for each x y point in the array)
-> relatively complex transformation of the above data in a x-y array of 8 bit values
-> generation of an histogram of those 8 bit values
and the claim is
-> same data
-> generation of an histogram of those 16 bit values
is impossible.
Jesus! How can one be so dense (sorry)! If they want, they can generate an histogram of how many pictures users take every hour or anything else they measure.
Now, of course, if a Leica executive said it, you can be sure it will become gospel for thousands of photographers. But that is utterly absurd: gazillions of histograms are generated on a continous base by zillions of sensor users who just want ot generate histograms.
Even if you don't care a bit about the technicalities, one has got to admire the logic of the process.
"we don't generate an histogram of the raw data because the picture doesn't exist, yet susprisingly the picture exists enough to derive a jpeg from that very same raw data and then an histgram of that jpeg...."
Priceless.