Which Callahan we talkin' bout here?
I think Tommy Callahan

You know big Tom Callahan's son - The heir to Callahan Auto Parts

It's a pity Clutterbuck didn't hit Ott with that bodycheck and then fight Richards.

Isn't that the truth - that would have been pure entertainment.
My point of posting this video is to show that fighting after what could be deemed a clean hit is certainly not some new phenomenon
EDIT - man do I miss that passion/intensity in those days!
UM. . . . . . . . . . . . . Did you watch the whole video and listen to the commentary at the end "It might have been an elbow . . . It might have been an elbow,
no doubt about that."
I'm not sure but I think Rule 46 says:
QUOTE
Rule 46 - Elbowing
46.1 Elbowing - Elbowing shall mean the use of an extended elbow in a manner that may or may not cause injury.
46.2 Minor Penalty - The Referee, at his discretion, may assess a minor penalty, based on the degree of violence, to a player or goalkeeper guilty of elbowing an opponent.
46.3 Major Penalty - A major penalty, at the discretion of the Referee, shall be imposed on any player or goalkeeper who uses his elbow to foul an opponent. A major penalty must be imposed under this rule for a foul resulting in an injury to the face or head of an opponent (see 46.5).
46.4 Match Penalty - The Referee, at his discretion, may assess a match penalty if, in his judgment, the player or goalkeeper attempted to or deliberately injured his opponent by elbowing.
46.5 Game Misconduct Penalty - When a major penalty is imposed under this rule for a foul resulting in an injury to the face or head of an opponent, a game misconduct penalty shall also be imposed.
46.6 Fines and Suspensions - When a major penalty and a game misconduct is assessed for a foul resulting in an injury to the face or head of an opponent, an automatic fine of one hundred dollars ($100) shall be imposed.
If deemed appropriate, supplementary discipline can be applied by the Commissioner at his discretion (refer to Rule 29).
So your example while entertaining and a great fight to watch doesn't really do much in the way of proving that there was retaliation in the past for clean hits . . . as there was no clean hit in the video.
(I do however agree that it has always been part of the game but think in the past it was a minor part of the game and has been occuring with more and more frequency all the time).