This an X5.6 flare with many interesting features. The left panel shows Yohkoh HXT in yellow contours, and microwaves in white contours over the mdi magneogram as background. You can see they line-up along the neutral line. Right panel is trace 171 A. 1. Magnetic transient-instant reversal of apparent magnetic polarity. Strong precipitation is implied. The bottom panels comapre the HXR and microwave time profiles. See the reversed trend in tw bursts. Microwave anomalous too because so weak. See the reversal of trend in the light-curves between microwave and hard X-rays.  The region has strong field and very energetic electrons, and why there is no strong microwave emission?—the environment is good for the radiation efficiency. So only reason thinkable was that  acceleration mechanism… the only place in the corona and ideal MHD. An expert says that it is very difficult to produce magnetic transiet in MDI Ni line, because so stable. –this scenario provides a solution.