Whilst I think this bird shows a number of pro WMH features (dark mask, pale crown, well-defined pale throat, little or no breast band, limited pale feathering on the leading edge), having read an article on the Birds Korea website, think the pale grey underside to the inner primaries and the crown streaking are pro EMH features. Both are known to hybridise, so maybe it's a hybrid. Anyhow, it would be good hear from those more familiar with WMH as it's a very distinctive bird.
