I was wondering about that. Probably should check with microchip first that the firmware update hex is a 'full hex' and not missing the bootloader block which may also contain some 'secret' information. Otherwise flashing the device with a PIC Programmer would definitely send it to heaven unless you were very careful to exclude programming to the bootblock and any other potentially protected code segments.
The device itself is probably not fatally damaged but maybe worth waiting for the updated programming software microchip have been promising.