You're right that I don't actually know. But in past instances where I've given this tip, I've had several people tell me privately that they hadn't used strict, and none tell me that I was wrong, they actually were using strict. Therefore I think it very likely that he isn't using strict.
Comment on Re^3: Hash versus substitutation efficiency?
That's perfectly okay. You did it for a good will, and you are always helpful. I just thought that, in this case, your conclusion was not supported by strong evidence and was logically defected, and it is better to make the right message to everyone.
In general, use strict is always a very helpful tip.