As I recall it, the Cod ‘ed responded violently to a strong tackle by Welbourne.
From where I was (side of pitch) it just looked like a fairly heavy tackle and, in those days, I did not really expect a free kick.
Welbourne was then thumped.
As I saw the overall, a legit tackle was made. Let’s assume I didn’t quite see it all from my angle – it was not a booking level challenge and surely not a sending off, IMHO.
I remember my comments to those not there that he got an 8 week ban for being violently assaulted.
I suspect that the ref was conscious (does that sometimes happen?) that it was a derby match and was trying to show an artificial even-handedness.