Is "detail" actually accurate?

I was playing with a new trinket, and i wanted to check the real damage based on crit etc… vs the actual tooltip.

I used a 435, Rotcrusted Voodoo Doll ( 36581 dots over 6s + 41647 at the end ).

Multiple test and details seems to be way off barely accurate, so it make me wonder how it can be accurate for large fights.

I did the test many time with nothing going on and just a target dummy. As an example:

On screen damage correlated with in game combat log :
129,621
Details reports:
88251

Did the test about 20 times always very off, It seems only the last DOT after the final explosion get counted the first 6 dots are ignored( actually overwritten by the big blast ), even though they start accruing on the meter right away.

Wonder if anyone has experience on how some of these effects are actually miscounted in raid/dungeons or if this is just a by product of using a target dummy. I could see ignites being heavily misreported by Details.

Edit: I try a few ignite tests and they seem a lot more accurate so maybe it is just this trinket.