Argon bootloader update went wrong. Will a debugger help?

I was updating Argon firmware from 1.0.0 to 1.2.1-rc.2 using DFU method.
After flashing device OS and tinker firmware. I reset the device and placed it in listening mode using the long press on the Mode button, then ran the: particle flash --serial command to update the bootloader.
The rgb led switched from flashing blue to flashing magenta for a few seconds then the device became unresponsive. I didn’t get any feedback on the console either. Powering down/up, plugging in/out from the computer didn’t get any sign of life. The device seemed bricked.

I suspected the bootloader update operation was botched for some reason and I’m wondering if anyone had a similar experience?
Also, do you think that getting a USB debugger to reflash the bootloader can get the device back to life?