bontu's last reckoning bug?

my opponent cast bontu’s last reckoning against my
single zombie creature. creature stayed alive, mana
was drained. is this a bug?

HH

It’s bad coding. It needs to be fixed.

It will also still trigger even if you chose not to in the confirmation dialog.

Confirmed. Very much akin to the old Harness the Storm bug where Harness would trigger even if you canceled a spell with a targeting/confirmation dialog.