In Deus Ex, there's a woman at the UNATCO HQ called Shannon who complains to Manderley if player visits the women toilet when she's there. Also, at the last visit at UNATCO HQ, player can buy equipment from her.
Does it appear even if I "visited" her in the toilet before? Does it have affect on it?
I don't have any direct evidence without re-installing and recording the game, but no it doesn't have any effect. Shannon is selling you the grenades in order to keep her secret. On an added note, if you attempt to hack the ATM she's at, it has 0 dollars. She's a crafty one.
There is currently a Let's Play in action on Deus Ex. In this first video you can see Manderly confront JC about being in the woman's restroom.
But then in this later video (which I'm pretty certain is on the same save and everything) you can still buy from Shannon.
I don't have an official source, but from when I played, the only effects were that Shannon would say something when you entered, and Manderley scolds you shortly after.
