AirlineFlightSchedules - unexpected behavior for operators

I have a problem with the following query:

https://flightxml.flightaware.com/json/FlightXML3/AirlineFlightSchedules?start_date=1515369600&end_date=1516579200&howMany=15&exclude_codeshare=true&airline=BCY&origin=EHAM

BCY is CityJet airline who is an operator on numerous KLM and Air France flights. I could access all KLM flights from EHAM with codeshare flights and the subset of BCY-operated flights would obviously be included. However, without exclusion of codeshare flights, the query result is massive.

I have two options and none seem to work:

  1. download KLM flights without codeshare flights. This is not an actual code-sharing, this is CityJet operating for KLM. I understand the logic behind exclude-codeshare flag is to remove all flights with non-blank “true_ident” field.
  2. download all BCY flights from EHAM that are not code-shares but are “true flights” (not having “true ident”, since “ident” is already the true ident). Since there are no “true flights” operated by KLM, those “true flights” should be operated and listed under BCY. To my surprise, the above mentioned link trying to access those flights provides NULL result, as if BCY had no “true flights” at all. Is anybody able to explain this behaviour?

The actual options require filtering but I am trying to avoid them:

  1. download massive KLM flights schedule and filter on KLM flights (no codeshare) + BCY flights (with KLM codeshare)
  2. download non-codeshare KLM flights and additionally all BCY flights (i.e. with codeshares) and filter the second set by rule true (TRUE?!) ident = KLM

Still, those solutions seem counterintuitive to what I would expect from exclude_codeshare flag (btw, the wording in its documentation is misleading, as it suggest it is in fact an include_codeshare flag).

Going deeper with Lufthansa, it becomes even harder to tell what is the key here and if the schedules are any way correct.

See, for example, the Munich-Tenerife route:

I suppose EWG schedule is totally wrong, as there is also no trace of EWG5982 on Vienna-Lanzarote route. EWG does not even operate on this route. EWG5914 on Vienna-Palma route is also a ghost flight.