Because Andreas also vouched for Neo & Bee...
Andreas disagrees with you.
"During that call I explained that I could only be involved as a technical advisor and that due to my limited time I could not endorse N&B with investors or take on a director position that would involve fiduciary or oversight responsibilities."
"I had no insight into finances, no oversight, no involvement in marketing or investor meetings, no contact with customers, investors or regulators. "
http://antonopoulos.com/2014/04/18/neo-bee-a-statement-by-andreas-m-antonopoulos-a-consultants-perspective/In what sense did he vouch for them more than this is an interesting company that could be big and be a viable and valuable business? In what sense did he vouch for them more than any other employee who didn't know the particular finances?
Indeed, I admit that "vouched" is too strong. He just let his name be used to legitimize the enterprise, and (like the other chief officers) did not see anything wrong with it until after the CEO ran away. Only then did people read the "prospectus" critically and noticed that there never was a real business plan.
I do not think at all that Andreas was conscious of the scam until that time. Also, as a tech guy he could be excused for not noticing the financial problems (unlike economist Tuur Demeester). But the episode does not inspire confidence in his competence as auditor, does it?