He knew.
On the day of Hera's death, most reapers gathered in the private facility where Hera was admitted. Deborah could remember how dangerous the atmosphere in the facility was at that time. The Reapers took up the entire floor; some were weeping quietly, while others were throwing huge fits.
Deborah remembered a few of them threatening the doctors. But alas, in the end, none of them could change their boss's mind.
Hera Cruel decided to die through a mercy kill. She didn't want to stay longer, thinking she had already settled everything. She disbanded the Reapers and got rid of any authorities from her people's backs. For Hera, not being a burden to her people was the right thing to do.
But for Deborah, that was the stupidest thing she had done. This decision led to Dragon exploiting Hera's vulnerability and resulted in June's death.