What type of fallacy is this?
. John says: "People are getting shorter"
. Mary says: "I will classify Johns claim as an outright lie, because people have been increasing in stature in the last 100 years, perhaps even longer that, this is a universally accepted fact amongst growth researchers"
. Bob says: "Mary's classification is false, because there MAY BE some indication that in the last year people may have gotten shorter, therefore you cannot classify it as an OUTRIGHT LIE"
My question is about BOB. I'm sure his reasoning is flawed because he employs a 'Fallacy of Exception': he discards a clear trend, not because of a proven break in the trend but because of a POSSIBLE break in the trend.
My 1st question: what is this type of fallacy called, precisely? I thought about 'reverse generalisation' but I can't find anything about that. I think Mary is right: John is telling an outright lie.
The mistake John makes is a sweeping generalisation without any proof and the proof we do have points in the exact opposite direction. So, Mary is right to call that a lie, especially because John doesn't specify a time period. Bob would be wrong in DEFENDING John with an exception, and defending John with a possible exception makes Bob even more wrong.
My 2nd question: Do you agree with me?
edit: For the sake of this question, let's assume that Mary is factually correct and that John has an ulterior motive for his claim (he sells small sized clothes or whatever) And yes, it's really true that on average people are getting taller, at least in the West.