Plot hole: Since the "Buddi" doll is designed simply to be a child's toy, able at most to carry items like a book or a banana, and Chucky in this movie is not a supernatural creature, it's hard to explain how it is strong enough to, for instance, carry the heavy watermelon across town and lift it in position. Even if his safety locks have been removed, a toy designed to be in the crib with toddlers wouldn't be built with the kind of lifting power shown here (we also see it assembled and it does not have a terminator skeleton or something like that, it's mostly plastic).
Continuity mistake: When Chucky is controlling the car with the police officer's mother inside of it, pay attention when she says the line "You hobbit, mother****er!" In that shot, she doesn't have her seatbelt on. However, both before and after this shot, she has her seatbelt on. (It doesn't get taken off until a few shots later).
Answer: The employee's bosses overworked and abused him. He was depressed, had emotional issues, and probably felt his life was hopeless. Before committing suicide, he wanted retaliation against the company for making him so miserable, so he disabled the safety protocols on the "Buddi" doll's computer chip. Mostly, it's a convenient plot point to explain how Chucky came about.
raywest ★