When using the API to call back to ArcGIS Server 10.41, geometries are always returned irregardless of the returnGeometry flag.
Snippet
private getGisDataQuery(field: string, value: string): Query { let query = new Query(); query.returnGeometry = false; query.outFields = ["*"]; query.where = `${field}='${value}'`; return query;}I found this question which may be related? https://community.esri.com/thread/203730-queryparameters-returngeometry-not-honored
If so it would mean this is more of a service, or server issue, not necessarily a bug with the API.