After an experience some years ago, I resolved that if I was making a comment about a piano for a potential customer, I would always do it IN WRITING, so as to have a record of what I said. A customer was selling her old (but 1950s refurbished) birdcage piano, and I was asked to comment on it to a potantial purchaser, which I did by phone. The potential purchaser pulled out of the sale, and maintained I'd recommended her not to buy it, which I had NOT. I had given a fair report on the piano and told the potential purchaser that the asking price was fair for the instrument. I ended up looking bad to the potential seller, and had to explain to her that I had not said what was reported. Putting things in writing is a protection, and allows you to make a very clear disclaimer.
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