https://twitter.com/RocketLab/status/1722377309070774526@NASASpaceflight
The reason the previous Electron failed, which - as Peter Beck noted - was "a highly complex, improbable, and evasive issue". And heck, he wasn't understating:
"After more than seven weeks of extensive analysis of the mission’s manufacturing, test, and flight data, the findings of the investigation overwhelmingly indicate that an unexpected electrical arc occurred within the power supply system that provides high voltage to the Rutherford engine’s motor controllers, shorting the battery packs that provide power to the launch vehicle’s second stage.
Exhaustive testing and analysis to recreate this failure mode has led to the investigation team’s determination that the arc was likely only made possible by the rare interaction of multiple conditions. Any one of these factors on their own would likely not have caused the failure of the second stage, but when they occur simultaneously in the low-pressure environment of space, they reach the threshold dictated by Paschen’s Law for an arc to form and travel. Paschen's Law is an equation that breaks down the relationship between voltage, pressure environment, distance between electrodes, and presence of gas necessary for an electrical arc to form and travel."
wow