Buzzer Beaters / Last-Second victories in WZFF

Warzone Firefight can be loads of fun, but it has its fair share of problems - super OP bosses, difficult objectives (curse those “Defend the Whatever” levels), and sub-stellar maps. But this one problem is easily the most frustrating problem I have with the game mode. For example, we beat the other bosses, but we have barely have time to kill the last one. Everyone dishes out anything at the boss, and we manage to kill it with less than a second to spare, clearly enough time to finish a round. But then the game decides to go on a different route…

Warzone Firefight decides that buzzer beaters / last-second completions are not counted towards completing a round. At least 5 seconds are needed for a round to safely proceed into the next stage. All our efforts in killing that one boss is put to waste, and many people (including myself) have lost many Firefight matches, losing out on huge XP and RP rewards as an unfortunate consequence. This is the most infuriating problem I’ve ever experienced, and this problem was also present in the Beta.

What is the meaning of this? Why can’t buzzer beaters / last-second victories be counted towards completing a match in Warzone Firefight?