Regarding the original topic, this post on page 4 does the best, but doesn't put enough emphasis on the critical point.
The sin was one of disobedience. Nothing else.
God Himself knows good from evil, and is good (the very Best), so having this knowledge cannot define one as evil.
Thus it is a misinterpretation of the event which may lead some to equate knowledge with evil. In most cases, this should be easy to correct, through communication.