Nope I'm not sending off for every trip, I'm just highlighting that in this case whilst what the player has done is not a full blooded kick, it's a red card.
What would you have done if instead of the GK going to ground, he turned round and punched the attacker? Sent off only the GK, or sent them both off?
In the pub games you refereed, because by your own admission you had no interest in progressing, you might just have got away with a dressing down (then again you might not, based on potential player retribution), however as you go up through the levels it would become clear to you that the only course of action is a send off.
Thanks for your humble opinion but it is just that, an opinion, and the educated guesswork at the end!! I'm sure there will be lots of similar incidents in the Prem and below this season that dont end in a straight red.... Lets see, I'll be checking your stated fact carefully!!!