In the Doctor Who episode "The Woman Who Fell to Earth" The Doctor removed
several DNA bombs from her companions and reinserted these into the data-gathering coil brought to Earth by Tzim-Sha (Tim Shaw).
The Doctor was not surprised when these found their way back into Tzim-Sha and seemed to understand he was connected to the coil.
Why then,
after Tzim-Sha had detonated the bombs, potentially killing him,
did The Doctor chastise Karl by saying "you had no right to do that!" for kicking him
off the crane? Surely he was as good as dead anyway? Although he appeared to teleport away before we saw him die, The Doctor had previously gone into great detail about the way DNA bombs worked and their deadly potential.