A word for a person who is made a villain by their circumstances, not necessarily by their actions

I was watching the movie Leon: The Professional. The protagonist, Leon, is a hitman — not somebody we traditionally sympathize with. The antagonist is a crooked DEA agent, pretty despicable himself.

Near the end, Leon is gunning down dozens of DEA agents who've been ordered by the antagonist to kill him. As the viewers, we're supposed to support Leon as he kills cops who have done nothing wrong themselves — they're just following (presumably reasonable, and since Leon is actually a hitman, perhaps actually reasonable) orders. Just because the person giving the order is the villain, they end up dead, merely doing their usually noble job (and honest cops generally have the viewers' sympathy).

I'm asking specifically about the DEA agents here: Is there a word or a phrase for this situation or literary device — where I'm made to feel that somebody is evil because of their association, where they've done nothing wrong, and they could even be considered the heroes from a different viewpoint? (Say, Leon were the villain and the cops had finally cornered him — I'd feel bad for these cops as they were gunned down). I checked the movie's entry on TVTropes.org and I don't see anything that seems to describe this situation accurately.

Solution 1:

Characters such as Léon are anti-heroes:

a central character in a story, film, or drama who lacks conventional heroic attributes:
with the age of the anti-hero, baddies and goodies became less distinguishable from one another

TVTropes' entry for antihero reads:

An Archetypal Character who is almost as common in modern fiction as the Ideal Hero, an antihero is a protagonist who has the opposite of most of the traditional attributes of a hero. (S)he may be bewildered, ineffectual, deluded, or merely apathetic. More often an antihero is just an amoral misfit. While heroes are typically conventional, anti-heroes, depending on the circumstances, may be preconventional (in a "good" society), postconventional (if the government is "evil") or even unconventional. Not to be confused with Big Bad, who is the opponent of Heroes (or Anti-Heroes, in that matter).

A related term often used synonymously is Byronic hero (Wikipedia):

The Byronic Hero is a type of character (an Anti-Hero, an Anti-Villain, or Just a Villain) popularized by the works of Lord Byron, whose protagonists often embodied this archetype, though they existed before him*. Byronic Heroes are charismatic characters with strong passions and ideals, but who are nonetheless deeply flawed individuals who may act in ways which are socially reprehensible, and whose internal conflicts are heavily romanticized.

Léon is one of the characters mentioned on Wikipedia's list of fictional antiheroes.

The crooked DEA agent would perhaps then be an anti-villain. Both of them are flawed characters (just like Lance Armstrong).

Solution 2:

I would suggest the DEA agents are pawns - placed in their situation by a higher power to the ends of that higher power, and deemed expendable. Their personal ethics are irrelevant, and their welfare of no concern, in terms of their designated function. Only their strategic usefulness is of value.

In the case of Leon, they are merely an attack by his opponent, Stansfield, that need defending against with counter-attack.