My wife was playing a game recently and was able to encrust her amulet and ring with the Service Pack crust despite only 3 points of alchemy, rather than the required 6, and a red cross showing next to the recipe. She did have 6 points in tinkering however. She also had the required components and they were consumed as you'd expect. I haven't experimented any further, so it may just be that recipe, and it may be related to the tinkering she had.
This should be fixed in the patch, and I believe is already corrected in the hotfixes. Unless this occurred within a hotfixed game. Then there may be a problem.