The client was not happy about being kept waiting and told the solicitor so in no uncertain terms. Later the client demanded an apology which the solicitor refused to give. You might think the solicitor was well rid of such an impatient, unreasonable client. On the other hand you might think commercial considerations and second thoughts about whether he had been discourteous might have persuaded the solicitor to accede and say sorry. Perhaps he was unduly intransigent.
Telephone calls create special tensions.
The client whose call you won't take because you're in conference might be miffed. The client who is sitting in your office while you take that call might be insulted. You can't please everyone so a compromise is sometimes necessary. The extra dimension in this case was that the complaint came not from the disgruntled purchaser but from the vendor. Because the solicitor also acted for the vendor.