Re: This is why you write down your constitution
"Instead of relying on oral history or tradition or whatever the heck it is you lot are relying upon here."
As has been said in other comments the British constitution is very largely written in a variety of documents from Magna Carta onwards, through the Bill of RIghts, various Reform Acts and Common Law.
What we have here is an unprecedented situation and when that happens there needs to be an evaluation of what is the best constitutional way forward. One way of doing that is via the court system. Doesn't the US also rely on its Supremes to interpret the constitution when the necessity arises?