I apologize if this was dealt with six months ago--I am a trade waiter and often try to avoid spoilers on books that I know I will pick up.
In the recent "Two Americas" arc of Captain America, Sam Wilson finds himself on a train filled with explosives that the right-wing terrorist group the Watchdogs plan to detonate at a meeting of political lobbyists. In stopping the plot, the Falcon throws (at least) two people to their deaths.
I have noted, as have most of the commenters in this forum, that Brubaker and Bendis have, without getting too gory, relaxed the general rule that super heroes (and, in particular Avengers) don't kill. This instance, however, seemed out of keeping with the other recent examples. In the past, when Bru has had a character, say Cap, kill it was plausibly necessary (ex. In a very similar example, Cap stopping terrorists from detonating a bomb on the subway train in Bru's first arc). Even if you had the feeling that Cap has avoided killing in similar situations on dozens of occassions in the past, it was hard to censor him for killing then. Indeed, Cap did not intend to kill the terrorists and I am sure that he would have been happy to have them live.
Similarly, although more ambiguously since Bucky generally intends the death of his opponents, Bucky has killed and the story has allowed the argument that killing was necessary--i.e., Bucky is a guy without powers and people are trying to kill him, so he shoots them. The same has been true for Bendis's Hawkeye (and, although there is no evidence that Clint Barton feels this is an important distinction, Skrulls aren't human and the killings were during a war (although, during "Avengers' Forever" Clint expressly notes that he won't kill even in war).
Sam's killing seems different. When the Falcon throws the Watchdogs off the train (and into a canyon), if didn't feel necessary at all. In fact, it was hard for me to view his actions as anything other than cold blooded murder.
Did anyone feel differently? And, does it matter to our perception of the characer?