The problem is it's still somewhat arbitrary how many times an umpire should say 'play' and in how many seconds interval as being human some are more patient and lenient while others impatient and strict. Going by such a subjective rule, in today's Viktor Axelsen match with Tian Houwei in the SSF , when Hawk-Eye already showed the shuttle was in but VA just couldn't believe it, refused to accept it and continued directing his protest to the tournament referee seated at their bench while ignoring the number of times the umpire was calling out to him (4 times ?) - wouldn't he be red-carded ? But as we know, the umpire let him off after only a verbal warning and the game proceeded. I mean rules are rules, or laws for that matter, but that doesn't mean there is no human side to it, the technicality of implementing it isn't perfect, that's why we engage lawyers/attorneys to argue our case in court, esp when it gives rise to somewhat differing interpretations for which the judges have to consider also the attenuating circumstances. Luckily badminton matches are not a life and death matter, so it's sometimes a matter of luck which umpire is on duty and his or her predisposition affects how strict or lax they choose to interpret and implement the subjective rules as opposed to objective ones such as whether a shot is in or out as called by the linejudges for which IRS (Hawk-Eye) where available can be called upon to arbitrate, otherwise the umpire will have to exercise their judgement in the case of a dispute. In life, there are always grey areas where a certain degree of latitude are exercised by those in authority according to their understanding, beliefs, competency, motives or even whims and fancies. Whatever it is, it depends on the person in charge and how we view him or her and what actions we can take to address the issue in any given situation. At times, even the same authority or umpire, in our case, can be inconsistent in their decision-making. I supposed that's life, you win some, you lose some.