Doesn't this question fall in to the realm of "is history a science"?
To which it can be, but not always, I'm assuming history that does meld with science is history that is verified with archeology (physical evidence). Not so sure I would ever class the study of hadith as a science unless it was backed up with archeology.
Maybe a social science, but one that is purely at the mercy of sources/chinese whispers.
Exactly there is no physical evidence! I think history does fall into science too because physical evidence is looked at (documents, ruins ect) Hadiths however as you have said is like 'Chinese whispers' what makes something with 2 witnesses credible - it's possible the witnesses could have worked together to state something for their own evil benefit! What I also don't understand is how Hadiths are so highly valued in Islam and why they call it science :/