I don't think he is Chris. It is most definitely HUNK. The Redfield line is most likely to throw people off.
Agreed, it's HUNK. See the comparison photo here:
He has HUNK's four known signatures: wears a gas mask, rides in an Umbrella chopper, engages in Umbrella's B.O.W. disposal and clean-up, and has light-colored hair and stubble. Another thing worth noting is that HUNK appeared in the Raid mode of RE: Revelations, and as one of three starting characters in RE: Mercenaries 3D, both games directed by Koshi Nakanishi, who also directed Resident Evil 7.
It also explains why the DLC starring "Redfield" is titled, "Not A Hero." Because in all likelihood he's not Chris Redfield, he's HUNK, Umbrella's wetworks man. Of course, I'm not counting out the possibility that HUNK
is a Redfield -- an unknown sibling, a cousin, a clone.
HUNK is presumably using Redfield's name and international reputation with anti-B.O.W. forces to lull Ethan into a false sense of security. We know that Ethan has weapons, engineering, and biochemistry training, based on his gun proficiency and ability to manufacture meds and ballistic ordnance. And we know that he mistrusts B.O.W. research because Mia had to lie to him about taking a B.O.W.-related gig. Yet he was still okay with her taking a gig that involved extended travel by ship, "babysitting" a mysterious VIP -- not a normal job by any means.
All signs point to Ethan Winters being "Ethan W. - Deceased" -- a Level 9 Umbrella scientist who was supposed to have been killed by Wesker during the Spencer purge, but who may have faked his death. This would explain both his lack of concern over B.O.W. monstrostities, and his fixation on Mia explaining her lies to him, rather than providing an explanation of what the crap is actually happening on this crazy plantation. It's why he says, "Took you long enough," when Umbrella shows up at the end.
It explains too why the Umbrella operatives talking on the radio seem to know exactly who Ethan is, and the risks he poses. Some players have proposed they're talking about Lucas, but if so, why not the same "shoot on sight" order as Eveline? Another user pointed out that Lucas may be a company collaborator, but it doesn't explain the deliberately ambiguous references to "him," rather than calling Lucas Baker out by name. They also say this person has been in touch with "you know who." Is this referring to Lucas being in touch with a rival B.O.W. company? Or does it relate to Ethan's phone call at the beginning of the game, perhaps to an Umbrella higher-up who prefers to go unnamed? It might be intentional that you can interpret it either way.
We can infer, too, that Ethan's previous experience and/or exposure to B.O.W. research could be the reason that he alone can resist Eveline's mental coercion. He's clearly infected by the E-series, yet neither he, "Redfield," or Mia seem concerned. Even Eveline seems to recognize this -- she instructed Mia to kill Ethan outright during their initial encounter in the guest house, and later went so far as to imprison him in a molded near-death state, where his mind remained lucid and safe, talking to the Bakers, even though Eveline claimed to Mia that he was dead. Maybe Eveline even thought he was. But ultimately, Ethan was able to escape the mold, which as we saw, turned members of the ship's crew into Molded B.O.W.s rather quickly. Then, he was also able to brush off Eveline's hallucinations and inject her quite easily with the Necrotoxin-E. She could neither kill, nor control him with her E-series infection. This may just be how Ethan's body reacts to it, with no connection to his past, but it's an interesting idea.
Regardless, the ending takes on a whole new meaning. Umbrella has been reformed, under new leadership, and they're bringing two former assets back into the fold. My personal theory is that Mia was an Umbrella freelancer or former employee. I also believe Umbrella is likely where they met, which explains their mutual familiarity with B.O.W.s. This is also why a B.O.W. company would contact her to work on a freelance basis transporting the E-series host.
When Umbrella started up again without Spencer and Wesker -- presumably sometime after the obliteration of Neo Umbrella in 2012, and before the completion of the E-series in 2014 -- Mia decided she could take the risk. She lied to Ethan, who still refused to trust Umbrella and presumably B.O.W. research in general, and went to work another B.O.W. mission. I'm still not clear whether it was Umbrella or a rival company that developed the E-series, but it's clearly at Umbrella that Ethan has a connection, as evinced by his dialogue and reactions. He and Mia don't even question why they would show up, despite the Umbrella name being connected with scandal and disgrace.
And now, the two of them are wrapped up in Umbrella's clutches once again. That's how I see it, at least. I believe Ethan was probably desperate enough to reach out to his old employer for backup, now that the guys at the top who wanted him dead are six feet under. Sure adds context to that, "Took you long enough" at the end, right?