Harambe was shot by zoo staff in the minutes after the boy fell
Isiah Gregg seen for the first time since Harambe the gorilla's death at Cincinnati Zoo
The complaint seeks the maximum penalty of $10,000 for the zoo, saying it could not keep a 4-year-old child out
Harambe was shot after the four-year-old crawled through a barrier and tumbled 15 feet into the enclosure
The boy did not look terrified as he sat beside the massive animal, shows footage
'The gorilla was shot because a tranquilizer would not have taken effect immediately' zoo director Maynard