Fault Current Distribution in Star– Zig Zag Transformer with source on Zig Zag side

One of my contacts on LinkedIn raised a question regarding Zig Zag – Star, ZNyn, transformer. If source is on Zig Zag side and (L-G) fault occurs on star side, will there be any current flow? In this case, even if neutrals of both Zig Zag and Star windings are solidly grounded, there will not be any current flow and the system behaves like ungrounded system! The explanation for the same is given in attached article. Zig Zag is really a mysterious connection in transformer vector groups    click here to open file