No. The reason that trading on insider information is illegal isn't that some third party is injured (if anything, martha's sales caused the third-party get a better price than he would have otherwise!) It's illegal because the officers of a company and the employees of a company are supposed to be doing the job of
running a company for the benefit of the shareholders, and there's opportunity for some pretty massive conflicts of interest if they're also playing games trading stocks / stock-tips instead.
And also because people think it's "unfair", like the stock market's supposed to be a game or something rather than a place that you can buy and sell stock for a price which is well-correlated with the company's prospects. :P