Garfunkel lists 5 conditions that distinguish post facto editing:
- The writer is not harming anybody by posting incomplete information.
- The writer acknowledges the incomplete areas in the original post, and actually does update it.
- The writer is initially writing for a close community of peers.
- The writer has a (different) day job, and can't easily contact sources.
- The writer does not have the stature to reach all necessary sources; posting first lets the sources know what/where the story will be.
Garfunkel leaves us a lot to chew on, and I think that his observations are a good start for distinguishing between blogging and professional journalism.