@frankiefiver
Not good seeing another company fail. Did you accurately measure the amount you tested? I'm not sure if it's just the angle but it looks like it might be a fair bit more than one gram. This would increase the overall amount of carbs in the solution giving a stronger reaction.
Ugh the nutritional info is done American-style with only the per-serving amounts.
Dividing the labelled carbs by the 29g serving size should equal around 0.05g of carb per gram unless I've done that wrong. This should definitely be a black result. We need about two or three times that to get a yellow result, which could happen if you added significantly more than 1g to the 10ml+water Benedict solution.
In fact that might be an interesting test to do, take a powder that tests black and add enough to reach around 0.2g carbs and see if it goes yellow. If so this could be a very easy mistake to make if people don't own micro scales, especially as powder density and teaspoon sizes are so variable