This basically reads like a textbook example of the misconception I wrote about in the last post. The author writes that Golden Age Batman used guns "All The Damn Time," if you read the post below, you will understand this is not true. The splash page (shown below) is used the same way it is virtually always used in these kinds of pieces, and references are made to the last pre-Robin story where Batman shoots two men from the Batplane's machine gun. This is literally the one and only time Batman shoots to kill anyone in the original darker comics. It is definitely not 'All the Damn time'.
Interviews with the creative team at the time reveal they knew they had crossed a line with that story. DC had their own internally enforced version of the 'comics code' not long after. The internal DC code is the one that had the rule against using the word 'flick' due to potential kerning problems, although many comics fans attribute this rule to the Comics Code Authority.