'He/she/it don't' is extremely common working-class dialects of English.
I heard it growing up in southern New Jersey from white and non-white
folk alike; and I hear it on this coast as well, again from all sorts of people.

In general, subject/verb agreement patterns vary somewhat wildly across
dialects of the English-speaking world. If we were to sample Britain
alone, we'd find several variations. I remember hearing a radio play set
in one of the Jersey islands. The dialect was quite remarkable; as I
recall, the number agreement was pretty much the reverse of standard
dialects: 'I were', 'you was', 'he were', 'we was' ... it was fascinating.

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Johanna Rubba   Assistant Professor, Linguistics
English Department, California Polytechnic State University
One Grand Avenue  • San Luis Obispo, CA 93407
Tel. (805)-756-2184  •  Fax: (805)-756-6374 • Dept. Phone.  756-259
• E-mail: [log in to unmask] •  Home page: http://www.calpoly.edu/~jrubba
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"Understanding is a lot like sex; it's got a practical purpose,
but that's not why people do it normally"  -            Frank  Oppenheimer
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