Brainerd's helitack 407 crash in 2024 got the final NTSB report released, I'm confused, what exactly happened?  MGT exceedances, IBF lights, overspeeds, but its all attributed to an "undetermined electrical supply disruption"?

https://web.ntsb.gov/investigations/?ntsbnumber=WPR24LA265#details

which triggered the CHECK INST light. All other gauges were normal. pilot panicked and entered an auto which didnt work out so well.

They had a rough summer. That was the second Idaho crash for them that season

Sure seemed like he exceeded the 5 minute limit on MGT at first.  75% torque up at those DAs would probably put ya in the yellow band on MGT.  But what's with the IBF light?  They clogged that puppy in just a couple of days?

The helicopter was only authorized to fly daytime VFR. The pilot was trying to beat the sunset to get home. He kept the MGT right at the top, exceeding max but dropping below the limit before hitting the 30 second over-temp limit. But then rising terrain forced his hand to keep the power up for a bit too long and he tripped the 30 second over-temp and locked in the maintenance caution. 

He continued on bouncing just above and below max temp limit. It seems the Moog MGT gage might have reached its limit on how many over-temps and could record, and subsequently performed its own power-off/re-start. When the Moog did its BITE check, the pilot misinterpreted it as an engine-out and did a full down auto-rotation…but ended up in corn that caused the bird to nose over.

 Bench testing of the MGT gauge did not reveal any anomalies, and

despite the in-flight display irregularities, the gauge recorded only one exceedance, which appeared to match the initial overtemperature indication observed earlier in the flight.