Yep, he did. And this is what people don't understand about radiation: a prolonged drizzle of it is more hazardous in the long run than a quick dose, even if it's higher.
The Gemini missions did not venture into the deepest, most intense regions of the Van Allen belts. But then neither did the Apollo missions. Nevertheless hoax believers who know of the Gemini missions try to argue that they didn't go deep enough into the Van Allen belts to know for sure they were passable, or to qualify as manned missions into them. That's all red herring, given the actual Apollo trajectories. Further, the model of the belts was derived from countless sounding rockets and from theory, not from the few Gemini missions.