The Great Oz
Member
It's unfortunate that you couldn't see it when you were done to keep it from being your problem. All anyone can do now is guess.
- Could be tip blooming from over-pressure or color loss from using an oxy-booster. Could be your fault.
- Could be the last guy and it was hidden by soiling.
- Could be tip blooming from the customer using a Dyson. Could be color loss from home cleaning, and that residue might be why the carpet was so dirty.
- Might just need steaming and setting the pile all one way to fix. Good luck.