The tester interpreted the results here . One of the tested brands, American Pure Whey, clearly has problems . Call it a positive control. By confirming those problems, the rest of the measurements gain credence. One company whose protein powder scored low is Gaspari. Unfortunately I cannot read their reply , which appears on my browser without text.
I look forward to more truth-in-advertising tests. It is really helpful that the data is public in this case, via Google Docs. Jimmy Moore (of Livin’ La Vida Low Carb) has measured the effect of several supposedly low-carb-friendly products on his blood sugar. His results are here .