The notion of "perfection" attributed to Adam or Jesus is WT language, not Bible language. I can't see any Bible text stating that Adam or Jesus were "perfect".
The closest Bible concept is "sin". It is not mentioned at all in the Adam story (legend). It is originally a ritual notion related to ceremonial uncleanness (for instance in the case of a woman cleansing from the ritual "uncleanness" or "sin" related to childbirth, or a cured leper reinstated in normal life -- no moral flaw involved...). However the word has also acquired a metaphorical, figurative moral meaning as we know.
Occasionally, Jesus may be declared "sinless" (Hebrews 4:15). This needs not mean "moral perfection" in an absolute sense. The basic sense is the post mortem justification of a man whose death suggested he was a serious sinner (cf. Galatians 3). Interestingly, Hebrews also employs the vocabulary of "perfection" about Christ: not to say that he was perfect, but he had to be perfected as a result of his life, death and elevation (2:10; 5:9; 7:28). This is probably an allusion to the vocabulary of priestly consecration, which suits the context (another subject). Anyway, there is no idea of terrestrial Jesus as a "perfect man", different from the others in this respect. Even Paul's heavenly "Son of God" theology, which is related to the Redeemer character of Gnosticism, doesn't declare the man Jesus sinless: by sending his own Son in the likeness of sinful flesh, and in relation with sin, he condemned sin in the flesh (Romans 8:3): the "Son of God" identifies with a "sinful man".
Finally, when NT texts (e.g. Matthew 5:48) mention "perfection" (or "completeness") as a moral or spiritual goal, it is a goal that can and has to be achieved here and now, remarkably unrelated to any cosmic millenial restoration, or to any "ransom sacrifice"...
My point here is that WT teaching is not to be confused with Bible teachings.