I wasn't clear. The instructions as written suggest to:
1) connect the bellbox "tamper out" to the panel's "Supply 0V"
2) connect the bellbox "supply 0V" to the panel's "Tamper return"
By their names I would have expected them to be wired the other way around, however the second table seems to suggest this wiring for all panels listed.
I understand that it's the same ground, but if this doesn't matter than why is there even a tamper return?
I have since experimented with these terminals at the panel end and during day mode if I disconnect:
1) The Tamper Return, then the alarm fires with a tamper alert (internal siren, tamper warning and external strobe).
2) The 0V supply, then the alarm fires with a tamper alert (internal siren, tamper warning and external strobe).
3) Both Tamper Return and 0V supply, then the alarm fires with a tamper alert AND the external siren sounds.
This all seems as expected (as #3 simulates a cut wire and the bell box battery kicks in).
My theory is that the tamper return is ONLY signalled by the bellbox when it keeps the main supply but is opened, which at this point I don't think I can test without a ladder and hearing protection :).
If so, then my suspicion is that the tables above are a misprint, but that it doesn't appear to matter which way around they are wired since the effect at the panel end is the same (as you say, a tamper alert in the case of a signal or cut wire).