Dr. Ben Carson says his puzzling laughter after saying he would have bum rushed the Oregon community college shooter ... had nothing to do with nerves or him being insensitive to victims.
Carson was in NYC outside the FOX News building -- where it originally went down on FOX & Friends -- and we asked what was really behind his chuckling. Remember, he did it again ... when we raised the shooting topic with him later that day.
Check it out, Carson tells us the blame lies with reporters and their questions, not himself. We went back and checked -- doesn't seem like a funny question, but everyone hears things differently.
Also, one guess what happened as BC walked away from our photog today. We'll try not to take it personally.