As far as I understand it the legal opinion is relying on the hope that the third prong of the Howey test means profits are derived "solely" from the actions of your company.
We've had this discussion elsewhere with someone claiming something along similar lines, so let me just paste that reply here:
Your understanding is correct but incomplete.
You correctly note that the Supreme Court has not yet fully ruled as to vertical vs. horizontal commonality, and that creates uncertainty as to Howey's 2nd prong (common enterprise).
However, Howey, as has been made abundantly clear since the original decision, is an AND test, not an OR test. And Blockmason's ICO clearly does not trigger the 3rd prong, the expectation of profits. Quoting from the legal opinion:
"As to the third prong of Howey, the expectations of profitability and advantage on the part of CP token purchasers in BlockMason’s ICO is a function of the token holders’ own decisions and efforts about how to use and develop the rights they are purchasing, as summarized in detail above. Any possibility of profiting from the future entrepreneurial and managerial efforts of BlockMason – as opposed to their past and proven efforts to develop products and services – is entirely speculative. The BlockMason IPO satisfies each and every formulation of Howey’s third prong, by any of the courts identified above. Far from expectations of profits flowing solely, or predominantly, from the efforts of the promoters, those expectations flow overwhelmingly from the decisions and efforts of the token purchasers."
