He was angry at Kevas Fajo and at Armus. And he was quite hurt by Ishara Yar's betrayal in "Legacy" - otherwise the final scene and final shot of the episode mean nothing.
A number of the writers - I can't say "most" without guessing - on the TNG staff disagreed with the "no emotions" edict when it came down in Season Three, and Spiner continued to play Data just as he had for the two years or so when it was assumed that he had feelings.
As soon as I read the thread topic, and started to think about instances, 'The Most Toys' popped right up, too. He'd been kept by a totally selfish, arrogant, cruel man who had no repect for life-even a woman who'd been loyal to him-or perhaps who moreso feared him, and he killed her as if she were nothing..as Armus so callously took the life of a brave, beautiful, and good young woman who Data most certainly was affected by-Psi 200 virus, or not....and I remeber him taking the little holo of Tasha out once, turning it on, and staring at it....as if...and the ceremony showed us 'he got it'...(Beautiful music in that powerful scene)...or what about in 'The Offspring', when Beverly said, after Data left her office, saying he was not capable of being the father to Lal that in other words a human might, etc....'now, why do I find that so hard to believe'...Data, embued for years with the basic rights to all for life, and peace, seeing by human example what counted most, found these acts to be morally contrary to what he'd been taught, and a total violation of something he so desperately sought...and acheived much along the way. Is this not why he has been so special to so many?