Yes, looks more like bud rot to me too.
Cutting it all away is your only option as the plant will not recover or repair itself from this or light burn either.
Once burned or rotted, it will stay burned and if it is rot, the rot will continue to spread.
Removing any humidifier and increasing ventilation will help stop the rot from returning.
Your plant will be just fine without any artificial humidity creating device, in fact trichome production increases in an arid (dry) atmosphere.