I have only witnessed the true straight up flight after being shot twice. The last time was a group hunt I had, a really strange foggy morning with a ton of frost on everything. The fog was just lifting, it was like a ceiling 100 feet high. The hit bird headed straight up and I yelled to my buddy to get after it as it disappeared through the fog hovering over us, we never saw it come back down. I said it went to heaven. Maybe it recovered and regained a normal flight, it could have fell and we just didn't see it, not sure, but it was a great memorable hunt.