I don't think he was hit in the chest. For one thing, body armor doesn't defeat rifle rounds (generally, unless the armor includes ceramic plates, which most folks find bulky and very uncomfortable). For another, the impact of a round hitting him and being defeated by body armor would knock him off stride, he certainly would have jerked at least some and not been able to speak. And it's possible the shooter did not have line of sight below his head/neck region.
The rifle shots sounded very rapid, too close together to have done any real damage assessment and adjusting.