I have had this conversation many times and it always boils down to a few things. There is a lot of technical science involved but I will try to explain it here as I learned it, from some of the top people in the business, which is as a laymen with a great deal of real life experience. There is very little argument that Gore-Tex is waterproof under practical field conditions as long as the laminate has not been damaged meaning that it keeps water out or will not let it pass from the outside to the inside of the shell. There is however still some controversy over the efficacy of it's vapor permeability or breathability in the common venacular but that is another discussion. Personally, I think it works although not as well as the marketing schmucks would have you believe.
If you were working in a steady rain and your base and or insualtion layers got wet while you were wearing a Sitka Gear Stormfront Jacket one or a combination of three things occurred. 1. The seam tape failed or was compromised somehow creating a path for water to seep in which is why I asked you where the wetness was because a leak at the seams is pretty obvious and easy to track down. 2. The Gore-Tex laminate was damaged somehow creating a point for water to seep through which is again pretty obvious to spot visually. 3. You wetted out meaning your perspiration did not pass from the inside of the garment to the outside in the form of water vapor either at all or not enough and it collected in your base and insualtion layers making you feel wet. This happens for a number of reasons but it is easy to recognize because it is not limited to a seam or one spot as described above, it is an all over thing like all across your back and shoulders. There is a fourth way which is showing up more often and that is through these so called waterproof zippers.
Wetting out happens for a couple of reasons. The durable water resistant treatment on the exterior of the shell has worn off and precipitation is not beading up and running off the exterior so it stays on the exterior surface and soaks through to the outside surface of the laminate. However, this still doesn't mean that the water passes from the outside of the laminate to the inside because it can't if the laminate is intact. Water in its liquid form is to big to get through the Gore-Tex membrane (but water vapor or water in gas form driven by body heat is smaller and passes through the pores). The water in this situation has the effect of sealing the exterior so that water vapor/perspiration from the inside cannot get out and that is the wetness that the wearer feels. The other way you wet out is when your physical activity simply produces more perspiration and water vapor than the Gore-Tex can efficiently vent so the excess perspiration collects on the inside of the shell eventually saturating the inner layers making the wearer feel wet. This is why active ventilation techniques are critical to staying dry and warm (in that order) for someone on the move in foul weather.
During high physical exertion in situations where you have to keep your shell on (like when it is cold, blowing and raining but you have to keep climbing) you have to use active ventilation techniques to help vent off the perspiration. Active ventilation is taking off your hat and gloves, opening pit zips, zipping down zip t-neck base layer tops, loosening the sleeve cuffs all the way so they slide down over your hands and act as a chimney or bellows moving air in and out as you walk, unzipping your double main zipper from the bottom and most importantly controling your physical exertion level so you don't sweat too much. If the weather is bad and you have no way of getting under cover to dry out, controling perspiration and its effect on the efficiency of your insulation and base layers can be a matter of life or death.
Here is the bottom line. If the Gore-Tex laminate is undamaged, it is waterproof for all intents and purposes, period. Wetting out and the control of perspiration is very complicated and takes constant attention and adjustment but is extremely important. No laminate breathes well if at all when the exterior of the shell is saturated with water. There is no magic bullet, the human body is a steam machine and that water vapor we give off constantly has to be dealt with. The harder you work, the more perspiration you produce making the task of managing that water more difficult.
So, do the shower test and see if you can locate a leak, if not then the only other answer is that you wetted out. Oh, by the way, Helly Hansen wets out too.
I have all of the Sitka Gear rain jackets including both the Stormfront and Stormfront Lite Jackets and have used them extensively in the field. None of them has ever leaked but they have wetted out which was my fault not the shells.