April is at work when a commercial painter's truck pulls up in front of her house. After checking the address on his assignment sheet, the painter starts erecting ladders against April's house and unloading brushes, rollers, and cans of paint. April has not contracted with this company, and the company has mistakenly put the wrong address on the painter's assignment sheet. When April arrives home, the painter is just finishing and he presents her with a bill. Is she obligated to pay? Why or why not?