According to Magic the Gathering Tournament Rules
If spectators believe they have observed a rules or policy violation, they are encouraged to alert a judge as soon as possible. At Regular or Competitive Rules Enforcement Level, spectators are permitted to ask the players to pause the match while they alert a judge.
Player A attacks with Pyreheart Wolf into Player B's creatureless battlefield, and does not acknowledge its triggered ability. Player B casts Psionic Snoop and connives during the Declare Attackers Step, and then declares it as a blocker. At this point, Spectator C steps in and asks the players to pause the match while they alert a judge.
Just to make sure we're all on the same page, there is nothing wrong with the game state thus far. Player A will have missed Pyreheart Wolf's triggered ability only if they do not stop Player B from blocking with Psionic Snoop, and Player B is perfectly within their rights to proceed with this line of play until Player A does so. Indeed, a judge would be unlikely to intervene in this situation even if play proceeded and they observed the triggered ability being missed. However, Spectator C believes that Player B has done something illegal by blocking with a single creature, and takes action accordingly.
Player B immediately recognizes what is going on, and asks whether Player A has any further plays during the Declare Blockers Step. Player A asks if they should wait for a judge to arrive, but Player B points out that Spectator C is not a tournament official, that therefore the players are under no obligation to follow their request to pause the match, and that they should continue play unless and until a tournament official pauses the match because time in the match is running down and a time extension would only reflect the duration of an actual judge interaction. The real reason Player B wishes to move forward is that even an unwarranted judge intervention at this point would likely result in Player A noticing Pyreheart Wolf's triggered ability before policy considers it missed. The players continue, and Player A does not stop Player B from blocking with Psionic Snoop. Several game actions later, a judge arrives and pauses the match.
Obviously the judge should issue a Game Player Error - Missed Trigger infraction with no penalty to Player A for missing Pyreheart Wolf's triggered ability, unless it somehow turns into an Unsporting Conduct - Cheating infraction. Should the judge issue any further infractions/penalties/additional remedies? Was Player B's assertion that players are under no obligation to follow the request of a spectator to pause the match correct, so long as the players do not believe that a policy violation really is occurring (or to cover Player B's case, a policy violation which that player is obligated to acknowledge, opponent's missed triggers wouldn't count), or is a spectator request of this sort as binding to the players as the request of a tournament official?