Guy is an idiot.
Back up media mounted when running this script and no backups elsewhere = stupid
When I was system admin at my prior job we had RAID5 plus Daily, Weekly, and Monthly backups.
The daily backups were overwritten every 7th day.
The weekly backups were overwritten once every month.
The monthly backups became a hard copy of the data to be retained and never overwritten ever again and placed into a safe.
We had failures a few times with the RAID 5 breaking and I had to rebuild the RAID array and push the prior days backup to rebuilding the data to the RAID.
*Given what this guy had for a company and clients content, it sounds like he skimped on a proper setup for multiple parachutes in place when the single backup plan fails. Reading this initially my thoughts were did this guy run a business with absolutely NO backup plan. In this case if this story is true he had the backup plan, but it was weak.
Its playing with fire to only have a single backup plan as for if a viral attack got in, and drives mounted he would have corrupted, infected the backup too. A business to the scale of what he "once had" should have had daily, weekly, and monthly backups in which there are multiple restore points to not lose everything, and if there is an infection that is discovered after mounting a backup media, you can deal with the infection and then go back further to where the infection is missing or if yesterdays data is destroyed, go back 2 days with virus taken care of and restore likely more than 99% of the data lost.