Practical Computer Science Problem

Programmer Bob writes one line of code every 30 seconds, and programmer Alice every three minutes. Moreover, Bob introduces a new bug every 15 lines, and Alice two bugs every 7 lines. Whose fault will it be when the client's application will freeze for the first time, given that Alice writes Delphi and Bob writes assembly?

The team as a whole is at fault; Shared victory, shared defeat. People won't pay the money required to get NASA space program level software auditing.