I don't think the example of checking in someone else's bug is a very good one. If I checked in something that had code from other people I would see it very easily, and if I did not think there was any way my code should have affected the autocomplete then I would assume the code I checked in which was not mine broke the autocomplete.
Matching it to the example of the papier mache cow doesn't really work because the papier mache cow hides the real cow but it is very easy to see that your code was also checked in with other people's code.
Matching it to the example of the papier mache cow doesn't really work because the papier mache cow hides the real cow but it is very easy to see that your code was also checked in with other people's code.