Mr. Rice made it quite clear why he took issue. He didn't say Pelletier had done anything illegal, only that he had exercised poor judgement. The two are not one and the same. Read it again from the article:
Commenting on what Pelletier has written on the Internet about his bookstore experience, Rice said, I think he exercised extraordinarily poor judgment on that particular night (because) he had an open-top holster in the small of his back in an unconcealed fashion. . . .
Most professionals do not carry a gun there because its hard to access the weapon and hard to retain the weapon if someone wants to take it away from you.
Rice prefers holsters with retention features that thwart efforts to extract the handgun, and he advises students to place the belt holster at their right or left side, where it is protected by the arm.
As a firearms instructor, Rice views concealed-carry as a good way to deter crime because they dont know who is carrying.
Though it is legal to carry a gun in plain view, open-carry is not a bright idea, Rice said. You are a target. If someone comes in with criminal intent, the first thing he is going to do is neutralize any person with a weapon who can hurt him.
Mr. Pelletier did nothing to earn the poor treatment he received, but that is a different issue that what Rice is saying. Seems to me the author (R. Talbot) is including marginally relevant clutter to expand the story.
I took that comment completely differently. I got the impression the instructor was critiquing the difficulty of drawing from that holster and saying it was a stupid place to have your handgun stashed!