Inflow - far better to keep the speed up when turning downwind (in both these incidents, low speed was the issue) or you end up descending downwind with low speed, putting you more at risk of VRS than LTE. It's an old problem of flying orbits around a fixed point on the ground - the pilot is target-fixated and flys a constant groundspeed instead of airspeed. Loss of translational lift and the tendency to weathercock add to the mix and bingo! All aggravated by certain designs without sufficiently powerful TRs!