"Delete Version" and "Remove Item" are completely different transactions. You can consider Delete Version as a physical delete, while Remove Item is the logical delete.
With Remove Item, the item is not really deleted from the SCM repository, but rather it is made invisible in SCM as a D tagged version.
For example, itemA has version 0 and version 1.
Run Delete Version on itemA version1, then the version1 is actually permanently and physically deleted from the SCM database and therefore only version 0 remains.
Run Remove Item on itemA version1, a new version2 of itemA is created with a D tag. Since version2 is now the latest trunk version of itemA and is D tagged,
when the user goes into the dataview, itemA will no longer be visible. Therefore, from dataview, user can not checkout itemA anymore.