It would seem they actually did. [1] Goldman certainly didn't provide the best service here, but I don't think what they did were illegal.
The blame for going through with this transaction falls on the clients who refused to hire an accountant when Goldman recommended it and pushed for an accelerated schedule. Heck, they agreed to an all-stock deal without even having their bankers present. (Of course, the ultimate blame lies with L&H who committed criminal fraud.)
[1] http://dealbook.nytimes.com/2013/01/29/lessons-for-entrepren...
Also it sounds like he said she said on the all stock thing. The Bakers say bankers weren't around. Also any decent banker would be able to tell you to up your asking price to account for rolling hedging costs and/or other risks.