Ring-pull science

It's the simple ring-pull and it's surely a simple design-flaw. Cans used to have a pull-away-able ring-pull, disposable, throw-away and a litter contributor. So what do we do to solve the litter problem of this? To solve the two-part thing, can and ring-pull? We introduce a one-part thing, where can and ring-pull are as one.

So far, so simple. Litter problem solved. Did no-one stop to think that the ring-pull, rather than be thrown away (check) is now put back into the can? Yet the can has been exposed to, let's just say, the elements. Our packaging in general does it's darnedest to completely cover the product - we even wrap our fruit and vegetables before advising that they should be washed (we have wrapped and covered bananas - are we for real?). Yet the humble, simple ring-pull turns in on itself. What's been over it? What has the top of the can been exposed to? Never got that.