Back in 1986, Edward James Olmos answered a similar question with this answer:
"I don't see myself going, "Four killed on that drug bust? Ha, ha, ha! Sonny, you're really good." They simply don't give me any scenes where I can smile."
That being said, in the last scene of The Home Invaders (from season one), you can see Castillo grin, as Lt. Malone and Sonny chat just before Malone informs Sonny that he is retiring.
I hope this helps.
Edit: One other note about that episode. Tubbs does not appear at all in the episode. He was injured filming the previous episode. From the entire series, this was the only episode PMT did not appear in.
Drifting through lost latitudes with no compass and no chart