During the entirety of the beta phase various websites were used as sounding boards to post gifs, videos and clips of suspected cheaters possibly using aim bots and the like to exploit us honest, normal game playing folks. While Blizzard is encouraging all players to be on the lookout for rampant cheating by reporting suspect players to [email protected], they don’t want their player base to take to publicly shaming every player that’s able to do things like the guy in this video. 

As Blizzard put it:

That said, Blizzard is also claiming to take a huge stand against actual cheaters across the launch of Overwatch. They’re threatening permanent bans to ANYONE found cheating even if it’s their first offense. However, they also want to reiterate their first point about just how good certain players are. They don’t want people depending on particular playback methods for proof.

Basically, a play that’s completely legit and fair might look sketchy when spectated or viewed through the kill cam. Don’t let that stop you from hunting down actual cheaters and helping to banish them with fair reporting. However, you should realize that the Widowmaker who dropped you and three other team mates with perfect headshots is likely just that good.