Your argument is incorrect. :) Omitting semicolons is perfectly valid and correct syntax. The spec is explicit about it being allowed and how the code shall be interpreted: http://es5.github.com/
It may be a good rule of thumb to use the semicolons, because you have to be careful without them, but in the end it's a choice based on team preference. If you are a very pertinent and careful type of person, and you don't have any rabid illiterates on your team, going without semicolons makes perfect sense.