Measuring the output of a flashlight is surrounded by a large number of variables. The chance that two people measuring two lights from the same production batch end up with the same result is smaller than winning the lottery. If someone says that the second light is more powerful than the first light, you can believe him (her). But if the results from two lights and two people are to be compared, the least you should do is to make detailed notes of the how/what/when and then send that very light to the other person. And vice-versa.
To quote Tiger Woods: always use double protection, in case you make a hole-in-one.