Do you think this one is okay in grammar? I think the right one would be: If he doesn't hear from me five minutes... Thanks for your help.(There's no mistakes in this script, I have made sure that T-Bag said "don't", not "doesn't" by watching the show)

T-Bag: Yeah, before you do, I have an announcement to make. I've been growing leery of the way you all talk, like I'm a lesser man. So, I bought an insurance policy. I called up my guy on the outside, and I told him about our plan. And I told him, in all likelihood, I'll be seeing him next week, but... if he don't hear from me five minutes before the escape, and 20 minutes after, I told him to call up the warden, blow the whistle on the whole thing. So if you all got ideas about getting rid of me... I suggest you make other plans.
You're right, WBB. It should be "doesn't. But in this case the mistake is made intentionally for style. In a story like this, the author can help to describe his characters by the words he puts in their mouths, or the kind of English they speak. These guys don't seem to be college graduates.

Regards, - A.
WBB-EFDo you think this one is okay in grammar?
No, but as Avangi says, when an author creates a character, he has to be true to the way that character speaks. If the character in a story, film, or novel is the kind of person who makes certain mistakes in grammar, then the author will write the story so that that character makes those mistakes.
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In "GAME OF THRONES season 3, 1 : the redhair girl said "if he don't " like you...
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