The go to combat shortcut is pretty universally accepted in both regular and competitive REL. Even the way he argued with his trigger wouldn't have worked since Heart of Kiran needed to be a creature to even be an eligible target for the triggered ability.
In Magic online you would have passed the beginning of combat as well if there was no target for the trigger.
But you're talking about making rules based on what may or may not be the standard method of communication of a human. You can't just shortcut words or thoughts of a person, even if you could do so digitally. That is absolutely ridiculous.
I am a player that ALWAYS says "enter combat", and I still think universal acceptance of moving a person past several points of priority in a phase makes absolutely 0 sense unless they explicitly say "declare attackers". In fact, even if you go into the rules of magic, declaring attackers is specifically referenced as a step within the phase. Why should we verbally assume that everyone wishes to move to that declaration when they don't say the declaration in the first place?
I missed it, what happened exactly?
Basically Cesar said "combat", and the judge, the player, and the head judge decided he meant "declare attackers".
Completely different verbal meanings to me, not to mention that Cesar isn't a native speaker. You can't choose to suddenly erect verbal shortcuts in a game, and it is exactly for this reason, as mistakes are going to be made.