I have level 28 Trooper. After hours of leveling up, roleplaying and questing I have really attached to my character. I also have my favourite companions and my most hated enemies. So if something would happen to my companion and or my charater would choose something wrong I would really care.
One thing: I'm HUGE Sandtrooper fan. Sandtrooper is my favourite character in the whole Star Wars saga. So when I created my Trooper I named it "Sandtrooper", but I also wanted my character to be like Sandtrooper. Not just by it's gear, but also by it's character. In Episode IV Sandtroopers were looking for the droids, C-3PO and R2-D2. After interrogating the Jawas they killed them. Same happened with Uncle Owen and Aunt Beru. I really liked their tactics and way of investigating.
So when I was playing SWTOR on Tatooine with my Trooper I attacked group of Imperial Commandos. After killing them I interrogated one wounded Imperial. After interrogating him he said: "Please mercy, m-mercy...." In that situation I had three options:
1) Very well
2) Sure, why not?
3) No mercy for Imps [Kill him]
So the two first options are both Light Side and the third obviously is Dark Side. So then I started thinking, should I kill him or not. Well the Sandtroopers propably would just kill the prisoner. But would this affect in a bad way to my companion? Well option number one is too forgiving for my opinion: after all he's still an enemy. But on the other hand he's wounded and he already told me all the intel. After thinking a moment I chose option number two. But afterwards I feel like that I should've killed him - he was an enemy, and Sandtroopers kill their enemies!! Another thing that also got me into regretting this was that my affection on my companion had reduced by one. I know that its not much, but it tells that he didn't think it was the best option. It also might have been that it would've reduced even more by choosing the Dark Side option. What would have been the best choice then?