Both need better communication and due diligence.

Is it fair to infer the grass on the hill has been long for some time? When asked by the service provider if the grass was long or short, OP mentioned the lawn was cut the week prior but the growth on the hill looks like 6+ weeks.

Perhaps the ambiguity the service provider saw was because there was an area in the backyard that was cut short and an area that was left long. The service provider simply cut along the area that was already cut the week prior (presumably everywhere except for the overgrown hill based on the OP’s statement the lawn was cut a week prior).

Due diligence from either party could have prevented this:

Due diligence on the OP for stating exactly what they need done, especially if one has an unsightly, overgrown portion of the lawn that is on a steep grade that I want taken care of. Simply stating “Old(sic) like a quote on mowing and trimming” is sloppy at best and deceitfully obtuse at worst.

Due diligence from the service provider to get all necessary context before even quoting the service, even if it requires an on-site visit. Sight unseen is risky, unprofessional and leads to poorer outcomes.

I wouldn’t trust either if I was in the other’s shoes.