He was probably also trying to worm his way into that woman's confidence, if the incident in the movie was true. Reporters are slimy like that.
Not that it matters, but Woodward was barely a reporter at the time of Watergate. He never went to J-School (which is probably a plus) and had only worked for a year on the (laughable) Montgomery County Sentinal.
This was his first real story. Which is why they didn't follow any known journalistic rules (as slack as they are) and they felt comfortable lying their asses off.
Woodward became an instant and never learned the concept of fact checking -- or truth telling. Of course in that respect it is fitting that he is the patron saint of modern journalism.