[algore]

if the bot can pass the Turing test it might be unlikely you could tell.

Even if you meet the bot in person, it might be hard to tell (unless it identifies itself as a bot)

Even Phillip Dick had problems with that.

[AndyJackson]

if the bot can pass the Turing test it might be unlikely you could tell.

If you can tell it did not pass the Turing test. That is the definition.