Personally I'd see that as a favourable thing to see in a sellers feedback. The refund doesn't say full refund, and it does extensively say that the seller has good customer service. I for certain would feel comfortable buying from a seller with something like that in their feedback.
So too might a potential scammer, but I would be surprised if scammers spend the time searching feedbacks for the same. Even if they do, a prudent seller only gets burned once, blocks and other tricks to identify repeat offenders can minimize the risk.
The negative feedback here is generally speaking relatively painless, it could be viewed as postal mishandling or perhaps seller mispackaging but it isn't specifically directed at the seller. If it were me, I'd have replied with similar notation that negative feedback was the first communication and "while I try my best to package items carefully there is only so much one can do and sometimes damage results in transit. In those cases I'm happy to work with the buyer to try to resolve the issue, if there is one". That also demonstrates the customer service orientation aspect.
Nobody likes negative feedbacks, generally our feelings are to react and oftentimes over-react. It is human nature. That's why I have/maintain a bunch of responses so I have stuff I wrote when I wasn't infuriated. They tend to be very much more customer service oriented, and I try to make myself wait a while before I respond. That is VERY hard to do.
