I often wondered what that statement meant. I always thought it meant that sometimes with the best of intentions we do something only to realize it caused more harm that good.
I am in the midst of this harmful outcome, albeit on a small scale. After sending a number of email Fwds to 'friends', I am at the receiving end of a few rebuttals from those same friends for sending wrong information.
The manner in which the rebuke took place was embarrassing to say the least, seeing as everyone who was on the email chain was also informed of my mistake, and my only hope is to never be so arrogant to people whom I consider friends. The information in the email was wrong, that I admit. But to be admonished like that, was also wrong.
A genuine friend is rare indeed.