BART officials emphasized that the video may not tell the whole story.
Passengers onboard the Pittsburg-Baypoint bound train say 37-year-old Michael Joseph Gibson challenged them to fights and used racial slurs just before a BART officer apprehended him. No one was injured on the ground when the glass shattered and fell 30 feet below, at the West Oakland BART station, but the officer suffered severe facial lacerations and a concussion. Gibson had minor cuts on his arms and hand.
"At this time we don't know what broke the glass. The investigation we are hopeful will reveal that," said BART Police Commander Daniel Hartwig.
Police say they'll be examining the video carefully to see who was at fault when the glass shattered.
"I raised him," said Michael Gibson's grandmother Margaret Gibson.
Gibson's grandmother says he left his aunts home, in San Francisco, and was going to his home, in San Leandro, around 5:30 Saturday evening.
"If he was so violent that he couldn't control him I give the officer all the leave he needs. But according to that video it wasn't like that," said Margaret Gibson.
BART police would not comment on whether the officer used proper use of force, but they say their guidelines on the "use of force" are clear.
"There's definitely a guideline and it starts at the basic level of verbal commands," said Hartwig.
What's not clear is if you hear the passenger or the officer giving those commands.
"Officers that can't talk to a person without physically handling them should not go so far," said Margaret Gibson.
Gibson's grandmother says her grandson was discharged after going through Army boot camp and he's been diagnosed as bi-polar. His aunt said he has been in jail at least 15 times in the past year.
Michael Joseph Gibson is in jail charged with felony battery of an officer causing injury, resisting arrest and public intoxication.
The officer, who is recovering on leave, spent six years with the Contra Costa County Sheriff's Department before BART hired him in May of this year.