Does Odin wipe system image when flashing a new Rom?
As stated here by user90492, dont use the NAND erase all. It will completely wipe the NAND including bits required to boot.

Odin should theoretically wipe the partition before writing on it as it does a write by block. Odin did not format the data partition resulting in old contacts data being present. The tarball file you used must be missing the blank data which is typically used to overwrite the data partition.