While it's up top, I have found another glitch - there was a change recently that allowed you to travel again domestically via point of origin
eg. MEL-SYD....NA/EU/AS...-PER-MEL-SYD

(Change talked about in this thread )

Just put my trip in which is about to be ticketed and got a validation error for going back to HBA:

1: HBA-SYD: 1st of 4 (Southwest Pacific)
2: SYD-HNL: intercontinental
3: HNL-DFW: 1st of 6 (North America)
4: DFW-MIA: 2nd of 6 (North America)
5: MIA-PTY: 3rd of 6 (North America)
6: CUU-DFW: 4th of 6 (North America)
7: DFW-YVR: 5th of 6 (North America)
8: YVR-JFK: 1st of 1 (North America Transcon)
*8: YVR-JFK: 6th of 6 (North America)
9: JFK-SNN: intercontinental
10: LGW-DBV: 1st of 4 (Europe)
11: SVO-HEL: 2nd of 4 (Europe)
12: HEL-RHO: 3rd of 4 (Europe)
13: WAW-HEL: 4th of 4 (Europe)
14: HEL-NRT: intercontinental
15: NRT-HKG: 1st of 4 (Asia)
16: HKG-CEB: 2nd of 4 (Asia)
17: CEB-HKG: 3rd of 4 (Asia)
18: HKG-SYD: intercontinental
19: SYD-HBA: 2nd of 4 (Southwest Pacific)
Rule violated!!!! [HBA-MEL] Max 1 segment(s): Travel via original point of origin not permitted