Realistically, there is never the option that bob will become a double-agent or gain sympathy for his target. Bob is just skin baggaged over a different IC character, who controls all of his decisions to be unwaveringly in his/her interests. Bob has nothing to gain from this job, he's a true slave. I view this as at variance with good form in RP.
Let me counter. My first infiltration was Xaiah infiltrating Aegis Militia. Xaiah was originally created as a carebear alt. She was a Caldari created around the same time Bacch was in Star Fraction shooting the Caldari loyalists.
There was an opportunity to infiltrate Aegis Militia with her, so I did. I spent nearly 9 months in AM, and while she never had sympathies for their goals (ie, Amarr Victor [insert latin spam here]), she did get to know a lot of the pilots in AM. Xaiah flew in AT 4 for Aegis Militia (incidentally, about an hour before I flew with Bacch for SF--that was rather hectic) and did her best to perform as well as she could despite her true loyalties, and she did favors for members of the alliance not merely because it suited her purposes, but because she got to know and like many of the pilots. At the end of the day, however, her beliefs were stronger than any sense of loyalty or duty she felt towards the pilots in AM, and so when the time was right, she acted.
Had she truly been a slave, she would not have flown for AM in the tourney. It was a last minute favor begged for by some of the leadership because she was the only one online that could fly a particular ship, but she could have easily bowed out and no one would have held it against her since it was sprung on her at the last minute.
In any case, for all the "dat's not doin it right" comments about RP and infiltration, it will continue to happen. There are ways to prevent it from happening to you, though none are foolproof, but there
are ways to protect yourself from serious damage being caused. You make choices when you run an organization. How paranoid do you want to be? How much do you really care about your forums being leaked? Do you want XYZ group to have intel on your upcoming operations? Maybe you want to spring a trap and you know you're infiltrated so you broadcast something to the entire alliance with plenty of advance notice to ensure your enemies know what's going to happen where and when, but keep the second part of the plan close to your chest so that when they think they're springing a trap they're simply playing into yours.
To me those are the fun parts of the espionage game. I don't care what they ate for breakfast, if someone has too much control over the color of their socks or whether their parents were murdered by terrible horrible [insert your choice of pirates, slavers, or other boogeymen here] or not.
Then again, my view of RP starts when I log into EVE. I'm not actually a pilot, nor am I a capsuleer, and nor are any of the other players in my alliance. But when I refer to them I tend to throw around the word "pilot", tend to refer to my ship as "my ship" rather than "my internet spacepixels," and everyone on my TS3 server refers to me as Bacchanalian rather than Rick.