The dictionary defines follow through as:
- carrying some project or intention to full completion
- the act of carrying a stroke to its natural completion
The term follow through is most often brought up in the context of sports, and relates to the continuation of the stroke after the ball (such as a golf ball, tennis ball or baseball) has been struck. In business it refers to, for example, overseeing a project to completion.
Both of the examples above concern themselves with a game or business, depending on your point of view. The score at the end of either may result in penalties ranging from loss of prestige to loss of livelihood, but rarely do they result in injury or death (with the exception of self-inflicted wounds or association with organized crime).
From the point of view of those who use their guns for real, failure to perform follow through may have more serious consequences.