I think there's enough blame to go around on this one.
http://www.cnn.com/video/?hpt=hp_c2#/video/us/2012/07/11/pkg-mn-lawn-accidentally-killed.kare
1. Employees should have asked the guy about what he needed to do
2. Employees should have some idea about the herbicides they are selling (or pesticides for that matter)
3. Customer should have read the label before using
4. Ferti-Loam should have put the information in a more visible place on the OUTER label. I'm sure other manufacturers don't do either. However, see #2 and 3 above.
Here are some tips so it doesn't happen to you:
Pesticides: Safe and Effective Use in the Home and Landscape
Also see the Pest Notes on Managing Lawn Weeds and Managing Weeds in the Landscape and Quick Tip about Weed Control using Herbicides. These are also available in Spanish.