Question about GoBattleSim @biowp

I've been running some Sims of SD/SE Ttar Vs. Flareon with dodge all strategy. How does the sim decide when to fire SE? When going to the log of some of the Sims I noticed a strange behavior, in many of them the first SE is fired after more than 20 SD, when 13 SD should already completely charge the energy bar without taking damage into account. Is this the intended behavior or a bug?
It would also be helpful if you add the energy bar status in the log.
Thank you, GBS is a great tool.