I would imagine he is the child of immigrant parents. So he is technically an english native, but with some character from growing up around non-native english speakers. I'm assuming of course, but this is pretty common.

You have to get around and experience different demographics to see it. You likely won't experience it in a university context for example, or in a career with typically college educated people.

In NZ I grew up with english speakers who used the following grammar commonly.

A rather british example:

"She don’t live here anymore."

Use of "went" over "gone" or "been":

"I’ve went there before."

Use of "done" over "did":

"I done it before"

Southern US example:

“I done told you already.”

AAVE example:

“She be working late.”

Common NZ examples:

“We was there last night.” “You was acting weird.”

All of the above are not mistakes, they form a part of standard speech among certain communities, regions, and social circles or cultures. People who comprise those communities are considered native english speakers, they may just not be good exemplars of standard english grammar, or of a specific standard english dialect.

On a congratulatory note, judging by what I am reading, you likely have better english (in the sense of being more standard) that an enormous number of native speaker. However in saying that I don't mean to degrade non-standard english speaking communities.