David,
.. essentially yes .. ..
If the .Item on the LayersCollection fails an error is thrown. .. so if no error, the Layer exists, and you could pass back either the LayerObject or the true/false , depending on design.
This may be suitable when attempting to identify one particular item from the Collection.
As I said, this is probably getting ahead of ourselves, and diverts attention from the Collection iteration you were demonstrating.
Regards
Kerry