what kind of logic is that?
if you say "One can say that Yang changed his mind the other day", i'd say one can also say that another reporter made the other 30% story up too.
the "random post" may be shit, but it brings out the fact is that there are two contradictory stories by xinhuanet, and other two reports from sciencetime that reports the same event but never mentioned any percentage.
if you want to believe those reporters, that's your freedom. i don't believe mainland reporters because of past experience. let alone this time we have the two contradictory stories.