Sorry for the confusion, I was originally working on Pool Stats then went over to Virtual Server stats because I thought maybe it was an error in the return data.
The BIG-IP is showing the following:
Details Bits IN Bits Out
All 66.0G 45.0G
Ephemeral 0 0
Other 66.0G 45.0G
Statistic Name High Low
(No Cast) STATISTIC_CLIENT_SIDE_BYTES_IN 1 -331265964
(No Cast) STATISTIC_CLIENT_SIDE_BYTES_OUT 1 1331262815
(UInt64) STATISTIC_CLIENT_SIDE_BYTES_IN 1 18446744073378285652
(UInt64) STATISTIC_CLIENT_SIDE_BYTES_OUT 1 1331262815
**Edit: Fixed formatting, made the data tables to make it easier to read.