If you are gay, and your gay male coworker accuses you of something it looks worse than if you are a woman, and a gay male accuses you. So, yes, of course it is different. Look at this way, a compatible sexual couple is at higher risk of an accusation than non compatible sexual couple.
But a trustworthy employee won't do any of those things, no matter the gender. If you have an untrustworthy employee you have a whole other problem. They could accuse you of making a pass at them, or of stealing from them, bullying them... the list is endless really. I don't get the preoccupation with sexuality in that context.
