DE HFS Calculate Size larger than drive size!!!

[turnback101]

Not the first time I have seen it, and I am sure there is a perfectly good reason, but why is it when I sometimes do a ‘calculate size’ on the full root of a HFS partition, i discover the amount of calculated Data is larger than the size of the drive?

For Example I have a 1TB drive that I can read perfectly, but with Data Extractor, the amount of extractable data is 1.4TB.

[fzabkar]

When a new file overwrites part of a deleted file, the two recovered files will share the same space. One file will be intact, the other corrupt.

[trumanhw]

When a new file overwrites part of a deleted file, the two recovered files will share the same space. One file will be intact, the other corrupt.

Dayum! That's some knowledge there!
(Looks like about 15-20 years of Data Recovery acumen to me)