There are 2 reasons I can think of why he won't answer.

One, confirmation either way would label him or the employee a liar. If he confirms what the employee said is true, then his own (Jacob's) earlier statement, that he did not pursue the lawsuit because of the chilling effect it would have on research (or words similar to that), would be seen to be a lie.

Two. It seems they may be now receiving the attention of the SEC and have decided to batten down the hatches regarding any sort of public statements that could be used against them. See this press release.

http://host.wallstreetcity.com/wsc2/Autoflag.html?Button=Get+Story&DB=SQL&SID=330u8239&Symbol=STEH