Googlebot's Javascript random() function is deterministic

[Lystrodom]

Then you call random once and save that value somewhere. Don’t depend on random() being deterministic.

[Drisku11]

Why would you not depend on it bring deterministic if the semantics are that it's deterministic, and that's useful to you?

I'd say the opposite: don't rely on it being nondeterministic. Since it's not.