soon, Bob triggered his customer's paranoia. She assumed that Bob was laying the groundwork to cover his company's butt later in the project.
How do you earn trust? You earn trust by being trustworthy--by making commitments and keeping them. Trust is earned by sharing experience. "Trust me!" is a cliché for untrustworthiness--precisely because there is no basis for trust.
Good communication requires a degree of openness and is required for successful projects. Premature openness can lead to its own set of problems, as Bob painfully learned. Use a healthy level of paranoia to ease into a trusting relationship. Don't try to force the relationship's maturity too fast. Like the Great Communicator Ronald Reagan said, "Trust, but verify."