Well, at my first dojo shodan tests ran one to one and a half hours, including the weapons...but then the mid to upper kyu tests could reach an hour with weapons...
At my last dojo shodan was also one hour, at my current one it seems like 20 minutes is more the rule from what I've seen and been told.
At two other dojos that are 'adopted' by me when I travel, shodan is 45 minutes and nidan is one hour (didn't see a shodan test at one, only a nidan test).
So why did your sensei promote them when they were also criticised? Not having been there, one guess might be the critique was meant to encourage them to strive even higher, and also to show you observers what sensei holds as ideal for the next one to test, but that overall, between the test and other observations he felt they had what it took.