Attached is a plot of Thunderbolt data before and after the event. 2 seconds after rollover the Thunderbolt reported it was re-initializing the loop filter and 4 seconds after the event it reported is was starting to phase lock the 1PPS. The DAC jumped 0.023V V which is around 75 mHz of frequency change. The 1PPS jumped around 2936 ns. It looks like it is going to take a few fours to recover to its pre-rollover state.