[ta416425]

The number of engineers at Google Toronto is so small that they're the exception that proves the rule, though. For all intents and purposes beyond some very special cases (and the Hinton stuff) you can treat the site as having no engineering.

[balfirevic]

> The number of engineers at Google Toronto is so small that they're the exception that proves the rule, though.

Exceptions don't prove the rule.

[selimthegrim]

The point of this idiom is that they end up not being exceptions at all.

[angry_octet]

That is not what I understand it to mean -- rather, the opposite. That is, finding an engineer at the Toronto office is so improbable that it is remarkable, hence you are reminded that it is normally an engineer free zone.

There are some idioms that do mean it is unexceptional. You might be familiar with the Pratchettism "Million-to-one chances happen nine times out of ten."