For your own devices and use (provided you can configure your devices to all use your local nameserver) you really don't need to care (unless you, at some point, want to make use of whatever the true owner is offering at "home.com").
But, for any visitors, if they have their devices configured to use their providers name servers, or if they have configured them to use one of the public name servers, if you direct them to "home.com" for something on your local lan, their device will instead resolve "home.com" to the IP assigned by the actual owner, and they will not be able to access your lan local "home.com" services.