return() documentation incorrect regarding lambdas

So the documentation for return() says plainly that it will return from a lambda, ending evaluation of the function.

https://docs.puppet.com/puppet/4.10/function.html#return:

If called from within a lambda the return will return from the function evaluating the lambda.

So let's build a short manifest and use a function that evaluates a lambda:

with(1) |$num| {

  return()

}

This creates an error:

$ puppet apply return_bug.pp

Error: return() from context where this is illegal at /tmp/return_bug.pp:2 on node 

Reading the spec test confirms that this is expected behavior?
https://github.com/puppetlabs/puppet/blob/ebd96213cab43bb2a8071b7ac0206c3ed0be8e58/spec/unit/functions/return_spec.rb#L85-L94

I thought of perhaps creating this as a documentation bug, but this is failing on documented (and desirable) functionality.