Regulation FD was created specifically to deal with this issue. I think these excerpts might help clear things up a little:
"Regulation FD
a. Whenever an issuer, or any person acting on its behalf, discloses any material nonpublic information regarding that issuer or its securities to any person described in paragraph (b)(1) of this section, the issuer shall make public disclosure of that information as provided in Rule 101(e):
1.Simultaneously, in the case of an intentional disclosure; and
2.Promptly, in the case of a non-intentional disclosure.
b.1.
Except as provided in paragraph (b)(2) of this section, paragraph (a) of this section shall apply to a disclosure made to any person outside the issuer:
iv. Who is a holder of the issuer's securities, under circumstances in which it is reasonably foreseeable that the person will purchase or sell the issuer's securities on the basis of the information."
I highlighted the above phrase because it is so subjective, yet critical.
Here's an example to consider.
A person who purports to be a shareholder makes the following statement about a conversation that they had with a person acting on behalf of an issuer:
"I believe what Steve indicated to me was that the financials AND the S1 that would be coming out next week."
It seems obvious (to me anyway) that, if the financials and S1 did come out the following week, the company would have been obligated to inform the public simultaneously with its communication to the shareholder.....especially in a situation where the financials are overdue and the public has no reason otherwise to expect them "next week". It seems almost as obvious that, should the shareholder have purchased shares based on that information, that too would have been a violation.
The twist to the example is in the reliability of the information. If the financials and S1 DON'T come out the following week, both parties could have acted exactly the same way, yet it's not at all likely that either of them would be found to be in violation of the rule.
Fortunately, the latter seems to consistently be the case here. Fortunately, that is, unless you bought in reliance on the information.