Using the scrollTo technique is a more complex solution.
W3C has the preventDefault() method while IE has the returnValue property.
You don't need either though as returning false is also guaranteed to work.
Putting Occam's razor at work here, returning false is the simplest means by which to successfully do the job.
On the flip-side, if you do use the scrollTo method, you will in 6 months time have forgotten why it's there so you will need to either document that statement by placing a comment near it to remind you why.
Simple is best. return false and you or anyone else will be able to tell what's happening there.