Your link is ridiculous, it doesn't show the definition of unsubstantiated at all.
Unsubstantiated:
dictionary.reverso.net/english-cobuild/unsubstantiated
A claim, accusation, or story that is unsubstantiated has not been proved to be valid or true. open to question, unattested, unconfirmed, uncorroborated, unestablished, unproven, unsupported
^That's a definition
edit ^
Still waiting to hear about those ladies driving new mercs.
I saw brand new cars and very expensive Mercs driven by young women. They can't all be driving their husbands' cars.
How many out of how many? i saw hardly any new Mercs being driven by young ladies in all the time i lived in Wroclaw.