Saying something is theoretically *plausible*, and claiming it is *true* are entirely different things. I said it was plausible. Only if I was claiming it were actually so would I ever need hard evidence. I made no such claim.
This is true to an extent but the nuances are so subtle as to really render them virtually indistinguishable.
these are the first definitions to come up on google, and they are not merely subtle nuanced differences "virtually indistinguishable" -- they have very clearly defined separate meanings that are not interchangeable.
1. (of an argument or statement) Seeming reasonable or probable
* - a plausible explanation
* - it seems plausible that one of two things may happen
1. An assertion of the truth of something, typically one that is disputed or in doubt
* - he was dogged by the claim that he had CIA links
* - history belies statesmen's claims to be in charge of events