The seller described the condition as excellent. It wasn't.
The seller offered a partial refund as an apology.
Had this been me, and had the seller paid up, this would have resulted in neutral feedback. Want positive? Advertise the item accurately next time.
But the seller didn't pay up.
And he ignored the dispute.
And eBay wound up issuing a full refund to the buyer.
To me, this is worth negative feedback. The seller didn't fulfil the promises made to the buyer after the initial issues were raised and a resolution was agreed. The buyer only received a refund because eBay intervened. During the dispute phase they will have received reminders that they needed to contact the buyer. Only upon a full refund being issued and negative feedback being left did the seller care enough to contact the buyer. At this point the sympathy card is played, because not having 100% feedback on eBay causes problems.
Feedback helps to ensure a better eBay for all that use it. People not giving accurate feedback is why there's so much pressure to be 100% positive. Instead of 100% being the domain of only the best eBay sellers, it is the domain of the majority. If we all gave feedback accurately, it would be easy to get a feel for how seriously sellers take their eBay commitments.