MSA can mean only one thing.

I've always wondered about a curious habit of Africanist archaeologists. They persist in calling the Middle Palaeolithic the 'Middle Stone Age' (MSA). Until yesterday I was bothered by the feeling that this practice was either fundamentally a misnomer or a term coined in the early days more or less contemporaneously with that of 'Middle Palaeolithic' in Europe, which would give them (in a charitable world) the right to use the term.
     Then, yesterday while I was eating my Post Honey Bunches of Oats [Does that count as product placement and will I get a big wad of cash for endorsing their product on my blog?] I was watching the news ticker up above and was drawn to an article in the November 8th issue of Dredging Today [You really can't make this stuff up. There's a web journal called dredgingtoday.com], in which I read

The site of what is now Rotterdam’s Yangtzehaven was inhabited by humans in the Middle Stone Age. At a depth of 20 metres, in the sea bed, unique underwater archaeological investigation found traces of bone, flint and charcoal from around 7000 BC. These finds are the very first scientific proof that humans lived at this spot in the Early and Middle Stone Age.

Aside from the confusion engendered in my mind by the presence of the Yangtze River in Rotterdam [and I thought Americans were geographically challenged!] at first I was a bit befuddled upon hearing a Dutch discovery described using the African nomen, MSA, rather than the term used ubiquitously in Europe, Middle Palaeolithic. Then I saw the date and was flummoxed beyond comprehension. Until, that is, I read 

Up to now, very little was known about this period in particular, the Early and Middle Mesolithic, so far to the west of the Netherlands.

And then it dawned on me. Of course the Africanist habit of calling the Middle Palaeolithic the MSA is inherently flawed [Unless of course you think that Africa never got out of the Old Stone Age, which I wouldn't put past some who've worked there over the years]. 
     The so-called Stone Age always comprised the Lower, Middle and Upper Palaeolithic (Old Stone Age), the Mesolithic (Middle Stone Age), and the Neolithic (or New Stone Age). What gives? Will one of you Africanists please step forward and explain this to me in plain English [i.e. not Afrikaans]?