There are lots of indicators in this text, and this breathless presentation is very much how modern LLMs present things.

Claude also loves to describe things as being "real", particularly saying "X is real".

In this case,

> The reallocations were real, but they were never the bottleneck.

There was never any indication or setup in the text that they weren't real, but it's how it justifies wasted effort, it insists that some phenomenon it corrected but failed to solve the problem "was real".

Another giveaway are nonsensical analogies:

> The predictor is like a barista who starts making your usual order the moment you walk in. If you are a regular, this is fantastic: the coffee is ready when you reach the counter. If you order something random every day, the barista keeps pouring drinks into the sink.

If you order "something random every day", then you don't have a usual order for them to be making, it's an analogy that doesn't work.

And of course, the smoking gun is:

> The smoking gun

It probably won't be a good indicator forever as it has been noticed so much, but it's a particular favourite of the current generation of anthropic models.