All of my close calls involve coming into corners too hot. First time I'd only been riding for about 2 months and came into corner that I didn't realize tightened up mid way thru. I was leaned over hard and could feel the rear tire sliding out. I thought I was going to put it down but some how just managed to hold it and carry out the corner. Felt really lucky there.
Second time was on a series of curves that i run pretty regularly, well one day the county chip n sealed the road and left little bits of gravel everywhere. My I came into the first corner fast with my buddy right behind me. Just as I entered the corner I saw the gravel and paniced. I got on the brakes too hard, locked em up but managed to stay pointing straight. I over shot the corner and just barely got stopped right as the pavement ended. I was convinced my buddy was close enough behind me he was either going to lay it down or crash right into me. Its a weird feeling just waiting for that impact. Luckily he was further back and saw my screw up in time to slow down.