Correct in-text citation, according to Harvard's referencing style I read somewhere that you can reference, the Harvard way, by stating the author, before ending the sentence with a date - like so:


  Author said this bla bal blabd bdalab d... (2017).


But, after reading through my dissertation, my teacher told me this was invalid Harvard referencing; and, he said I should cite the author like this:


  Author said this bla bal blabd bdalab d... (Author, 2017).


Is this true, or can I indeed use the proposed method?
There can be disagreement on how to reference correctly within a style. I have referenced in both ways that you cite, with no complaints from my tutors. I have also had papers published using both methods of citation with no corrections from the copy editors. 

However, I think what we are experiencing here is your tutor's preference. He clearly wants you to do things in method B rather than method A, for whatever reason. I am sure he has read through multitudinous publications, some of which use method A, though his own preference is B.

When I wrote my first essay for my master's I used footnotes for referencing. My tutor wrote on the paper that in-text citations were much better: neither was wrong, but my tutor was specifying a preference and recommending a better habit to get into. Similarly, seeing as yours is the one marking your papers, I would just go with it.