Does the verb in Gen 2:19 affect whether there is a contradiction (of when man was created) between Gen 1 and Gen 2?
The verb is imperfect, which won’t solve your problem. If it had been in the perfect tense it probably wouldn’t have convinced the fellow who is arguing for a contradiction. I think your argument that Gen 1 is chronological and Gen 2 is beginning the story of man is right on the mark, but I fear that those in the contradiction camp are not really interested in finding something to believe, but rather in finding something to refute. If Moses was the author (something they would probably not accept) then why would he contradict himself? Having set down the chronology in chapter 1, Moses looks at this matter in a way that prepares for the fall of man in chapter 3. God brings the animals to Adam for him to name, so that by so doing he can begin to rule over them. And yet in chapter 3 Eve will listen to a creature, who blasphemes God and tempts her to rebel against Him.
Further, the animals were brought to Adam in the context of his not having a suitable mate. As he watched pair after pair of animals come to him to be named, he began to figure it out that he had no mate. God pointed out the need, and then met it. In the next chapter, the need for the knowledge of good and evil is at issue. Adam should have come to see that God always meets man’s needs, in His way and in His time.
Anyway, I guess I’m saying that you won’t be able to convince someone of the truth by debating; only God can. I don’t think any evidence you can bring to the table will compel them to accept the truth. And remember, believing in the creation is a matter of faith (Hebrews 11:3).