Unfortunately this is not true.
If you really want to wipe the data from a drive without any chance of recovery, it should be wiped with a low level formatter at least once, twice if you're paranoid and three times if you work for the NSA
Darik's Boot & Nuke is great for something like this, and it's VERY thorough.
Darik's Boot And Nuke | Hard Drive Disk Wipe and Data Clearing
and believe it or not, smashing a hard drive doesn't render the data completely irretrievable. By most folks? Definitely plausible, but if someone REALLY wants to know this information, they'll get to it.