Whenever you find laezel dead at the githyanki patrol area and revive her
-How come she still has the tadpole when revived?
-We know from interactions the dragon rider orders her skull split and the tadpole crushed so any theories as to why it wasnt?
That's part of the unsolved X-Files again. As true as Scully and Mulder are my witnesses.

With some NPCs one can kill for sure the tadpole (Edowin), with some none appears or it is probably assumed that it dies at the same time in the host body (Brynna, Andrick, Kagran & his fellow), but this remains unclear... For the bosses Gutt, Dror Ragzlin and Minthara no tadpole appears for Minthara, for Dror Ragzlin yes and for Gutt yes or no depending on the approach.
Rumor has it that the tadpoles of the companions are more special than those of the followers of the Absolute. Concerning the companions and the MC: Even if the own character dies in lava and the body including tadpole should not exist any more, one can be revived by Withers incl. tadpole...