From the previous issue it sounds like the developer has proper legal representation, but in his place I wouldn't even begin talking with Haier until they formally revoke the C&D, and provide enforceable assurances that they won't sue in the future.
Also I don't know what their margins are like, but even if this cost them an extra $1000 in AWS fees on top of what their official app would have cost them (I seriously doubt it would be that much unless their infrastructure is absolute bananas), then it would probably only be a single-digit number of sales that they would have needed to loose to come out worse off from this.