The way the American legal system works this does not surprise me, after all, we have parents taking games manufacturers to court after their children grab a gun and run around shooting people. Here's a rough guess why that clause may be in there:
1) CAD Software is used at some point to design stand housing packets of cigarettes.
2) Someone under 18 buys pack of cigarettes.
3) Later that child gets cancer.
4) Parents of child sues the retailer, the tobacco manufacturer, the company who printed the packs, the manufacturer of the stand the cigarette packs were on and the manufacturer of the CAD package used to design the stand.
I've worked with lawyers, this is now unfortunately quite common.
The citry that built the road that led to the stand,
the truck manufacturer the pack were transported into,
the fuel company for providing fuel for the truck,
the tires installed on the whhels of the truck,
the clothes manufactured the truck driver was wearing
the electric company for powering the stand the cigs were sold,
the electrician that installed the light bulbs ... and it goes on...and on...and on....
Digikey doesn't have a tabacco section ( or pullution or wildlife protection or guns or speeding or driving drunk) so it must be translation of the American Law as understood by a German attorney with English skills not quite as good as he/she thinks it is.
When in doubt, throw in and the kitchen sink. And some ferrite beads. bzzzt