The term" Stockholm Syndrome" was probably created during this event, but that does not prevent the fact that the syndrome in itself might have be encountered and noticed before even without a clear name.
Maybe this psychiatrist had a "bias" regarding the behavior of the woman regarding his past experience.
In my opinion, there is really a Stockholm Syndrome even if it is probably not clearly definable and with variable geometry depending on the case. For example, in the corporate world, it is quite common to have employees being abused with them supporting their manager/hierarchy on the based opinion that their manager are doing that for the good of the company and so also for the good of the person.