Phil Bronstein’s column, critical of Gavin Newsom, appeared briefly on the SFGate.com site and then was pulled.

That prompted bloggers to allege a conspiracy since the Chron has been Newsom’s biggest media supporter for years.

Hours after the column was pulled, Bronstein and his replacement, Chron editor Ward Bushee, said the posting of Bronstein’s column on SFGate.com was a mistake, and that it was only supposed to be in print.

The Chron is testing whether it makes sense to offer infomation in only its print product, forcing those used to online news to pick up a printed newspaper.

Here’s what Bushee had to say:

Phil’s column was created from the start to be a print-only column in the Monday Chronicle. When we first started talking about the column, Phil and I agreed to try this as a low-stakes experiment. The experiment is not indicative of any larger plan by the Chronicle, SFGate or Hearst. It is not the start of a premium content initiative or a pay wall. But it was designed to test how different content models can serve different audiences. Each week Phil reaches a significant online audience with his blog, which is not available in print. By introducing a column by Phil that is different in its content and mission from his blog, we can see if it adds value to the printed paper by giving readers unique content that they could not get free online. As with any experiment, it will be evaluated at some point to see if we stick with it or change it. Unfortunately, the brief appearance of the column on SFGate this week made some people think we were pulling it off because of the content. That was not the case. The column was posted for a short time on SFGate through a misunderstanding and then pulled down when it was discovered.

If those online critics had only picked up a printed copy of Monday’s Chronicle, they would have figured out what was going on.