Bumba's "Denounce" is sometimes unsurvivable

Platform: Windows 10
ISP: Comcast
Type of Internet Connection: Cable
Internet Connection Speed: 99.3 Mbps
Date & Time: April 4, 2021 8:50 PM EDT
Frequency: Always
Character Name: Mischief
Race: Tarutaru Male
World: Bahamut
Main Job: Scholar
Support Job: None
Area and Coordinates: Sheol: Gaol
Party or Solo: Party
NPC Name: None
Monster Name: Bumba

Steps:

1. Fight Bumba until he enters his second phase and gains the ability to use Denounce.
2. In this phase, Bumba uses two abilities in a row whenever he gets sufficient TP. If the first ability is Denounce, it is an instant KO to all targets in range, dealing more damage than any player can withstand and ignoring all forms of mitigation.
3. If Denounce is used as the second ability in a pair, it deals severe damage based on target's HP instead of extreme damage, similar to Sajj'aka's version from Sinister Reign. This version is consistently survivable by all targets if handled properly.
4. Bumba using Denounce as the first ability in a pair seems entirely random, not tied to healing him or any other discernible action taken by the players. It can be used as the first ability after gaining access to it, resulting in a nearly unwinnable situation.
5. Given the discrepancy in behavior between Denounce used as the first and second ability in a pair, and the apparent randomness with which Denounce is used, I believe this is unintended behavior. This feels similar to Mboze's Tiiimbeeer, which was unsurvivable until its damage was reduced in a previous update.

Lots of enemies have potentially unsurviviable one hit KO attacks that aren't necessairly used with a particular pattern.