Hmm. Did you use exact match anchors?
Never even considered that an option to look out for. I wonder how many people are monitoring their link's backlink profile...If someone sent spammy links to your web 2.0s than it would pass on to your site. Use something like ahrefs and check the backlink profile of your web 2.0s. If someone found your web 2.0s and spammed them you can just remove the links pointing to your money site. Replace with some high quality guest post links.