I just watched TNG 3.22, "The Most Toys." Uh, what was up with the ending? Why was Data possibly lying to Riker, or possibly being blinded by his equivalent of emotion, not addressed? That's too big an issue to ignore.
For reference.
http://www.youtube.com/watch?v=_skkBMvlWBw
Data didn't intend to kill Fajo for crimes like kidnapping/theft, because of his "fundamental respect for all living beings". So he put up with an unacceptable situation while he tried to find a nonlethal exit. He surrendered his position and sat in the chair when Varria's life was threatened. But that could not stop his position from being unacceptable, or from him taking an exit if it became available.
But then Fajo killed Varria in retribution for an escape attempt, without giving Data a chance to surrender. Data's respect for Fajo's life cost Varria her life. In hindsight, killing Fajo would have been just as acceptable as letting Varria die by not killing Fajo. Not killing him sooner was a mistake.
Then Fajo demanded that Data totally and completely submit to him (unacceptable), otherwise he would just kill again. This set up a pattern. Data might have been stupid enough to bet on respect for Fajo's life a second time, but not against more than one life. And no matter how deeply Data submitted to Fajo, his intent to escape would always remain, and there would be a risk that Fajo would kill. Heck, this confirmed killer might kill someone again for something else, even if Data acts his part perfectly.
Data made a coldly logical decision to execute Fajo, and while he was coming to that conclusion, Fajo gave him a lesson in humanity (I know, Fajo's not technically human) by telling him that humans would solve the dilemma by getting angry and killing him. Not only was killing Fajo logical, but it was (apparently) the human-approved solution. So Data tried to kill him. Fajo believed that Data was incapable of killing. He was wrong. Data
doesn't like killing.
Then when the Enterprise arrived, the situation changed. Killing Fajo was no longer necessary.
When Riker asked Data about the weapon discharge, Data didn't lie, he omitted. There could be any number of reasons why he'd not actively want people to know that he actually tried to kill a human.