But the key here is "most people", most people don't know that distinguished engineer is a title at MS and would just assume that he was a well respected engineer at MS. It isn't fair to compare two dictionary definitions of a word, to what is a fairly little known outside the company title structure at MS. There were three descriptors of the word "engineer" senior, database and distinguished. Turns out Mr. Shamgunov's title was Senior Engineer, I didn't read it as his literal title but more like a description of what he did at MS. Database wasn't in his official title either but it still applies. Seems kinda weird that people are so touchy about titles, seems so unSV.
distinguished - "successful, authoritative, and commanding great respect"
Is English your second language per chance? Not meaning to be rude but you're taking things very literally and seem to think that MS has somehow trademarked the word "distinguished."
If a school gives out "Academic Excellence Awards" to it's students, it doesn't mean that only those students who get the award(I don't know what Mr. Shamgunov's title at MS was) can describe themselves as excellent students.
As noted below, the fact that it's in lower case and precedes the words "senior database" makes it pretty clear that it's being used as a descriptor not as an official title. Especially since unless you're from MS, no one would even know about it.
I see such literal interpretation of English from immigrants that come to the US when they are adults. Unsolicited advise, try reading fictional books to get a hang of colloquial English :)