Given the time constraints and news as entertainment values of present day news, you could practically count on your fingers and toes the regular reporters who are "gathering news from after-the-fact interviewing and document collection". Most news is done by reading or listening to the PR and write it up. Sometimes a phone call or two is undertaken to get a quote that isn't in the press release.

There are some news stories that have been done with more digging, but then there are some blogger's stories done with more digging too. The main difference at present is that one method requires the purchase of an expensive organization.