Earlier quoted context omitted.
Because developer one wrote if (statement) one; And developper two added if (statement) one; two; too quickly
Sure, but how often does this happen in practice? I have worked with 'no convention'/'multiple conventions'/'mostly no braces for single statements' and have never seen this particular mistake. I can see how it would be difficult to track down, on the other hand, braces for single comments add to line noise.
A lint tool checking for suspicious indentation would be a better use of labour.