A person who has contributed to the capital of a business conducted by a person or partnership erroneously believing that he has become a limited partner in a limited partnership is not, by reason of his exercise of the rights of a limited partner, a general partner with the person or in the partnership carrying on the business, or bound by the obligations of such person or partnership if, on ascertaining the mistake, he promptly renounces his interest in the profits of the business or other compensation by way of income.