In the episode 'Orac' Ensor says that Orac's key is a simple on-off switch (at a guess some sort of circuit-breaker equivalent - speaking non-technically). Vila's lock-opening skills would include a basic knowledge of computer functions on a practical level (and perhaps this is why Avon is so snide about Gan - he is effectively computer illiterate). Even if Avon pocketed Orac's key automatically he might expect Vila and Zen to be able to 'patch something up.'
Alternatively, Avon might have expected Vila and Cally to think back to when Blake did something similar in 'Trial' - and that if they did not, Zen would tell them anyway.
Though he probably did expect to be in a position to get in touch with the Liberator within the specified period - and even Servalan was not aware that the 'cloud' was active - whether it was 'cleaning fluid' or something else.
The Links and Moloch might be different because they were 'evolved' with different intents - the 'ancestors' of Moloch wanted to be ignored (simplistically) and to have a better interface with computers, while the Federation (assuming they restarted the experiment on Terminal once it had been moved to its new location) might have aimed at something else. Or - is there a passing nod to the Eloi and Morlocks in HG Wells' 'The Time Machine'?
It would be interesting to know when the Teal-Vandor war games were set up - the Federation might well have 'borrowed' the technology of the sensor net in an attempt to create the limiters. The Federation in selecting subjects for limiters might well have divided 'violent criminals' into two groups - the ones which were persistently so (eg the crimos and Doran) and those who 'acted violently in a specific set of circumstances' - which Gan (seemingly) was (even if his actions were directed against the 'police'). The Federation were attempting to ensure the latter group could be reintegrated into general society - but the limiters did not 'work.'
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