Series star Stephen Amell and executive producers for the series had separately told fans to expect Bennett's villain, who was the big bad on the show's fan-favorite second season, with EP Marc Guggenheim sharing a set photo that included a man in Bennett's Deathstroke costume.
Bennett had tweeted that on Monday that he wasn't returning to Arrow, and then followed it up yesterday with a tweet that read, "Enough b.s about d.s!!! FACT: Deathstroke Arrow are currently filming in Vancouver IS NOT ME. I am in Auckland filming The Shannara Chronicles."
Bennett has not appeared on Arrow since a season three episode in which his character was easily bested by Thea Queen, Oliver's younger sister, in a fight. After that episode, Bennett criticized the show. That public criticism, coupled with a then-recent alteraction with a fan at a convention, led many viewers to assume that they had seen the last of his character.
Deathstroke appeared during the "dream sequence" portion of "Invasion!," The CW's three-night, four-show crossover, although the character never removed his helmet, and it seemed obvious that the brief fight scene in which he appeared was not something Arrow would have flown Bennett to Vancouver for.
While Bennett was not currently filming Arrow, it seems that he is or will be at some point this week. The "other" Deathstroke was likely a stunt performer, there to shoot some scenes for which Bennett wouldn't have removed the character's trademark helmet.
He's also only one of a number of reported returns, including Nyssa Raatko (Katrina Law) and Captain Boomerang (Nick Tarabay).
More Arrow news: