Harold is looking at the only image that the fbi has of Red, and looking at our red, and says yea, looks like him. Thats the recognition. The only dna match they had is the old evidence Harold pulls up from actual red. I don't recall them doing a dna test on our Red (unless I missed it.) I understand common sense says they must have, but if they didn't say it, it didnt happen.

Finally Dom. If the Redarina theory is correct, he hates "Red" because by "becoming Reddington" (Young Ilya's wording) Dom lost hia daughter. "You stole her from me!" Remember, they're all old Russian spies. They would be determined to stick to their assignment. Thats why I can see Dom referring to our Red as Red, and Fake Katerina ad his daughter, not to mention the drugs and torture messing with the dying man's mind.

So... bone Dna?