Having both sets of cameras down might initially look suspicious but of course they might well be linked. How suspicious their being down at all is is a matter of perspective, for all we know they could have been in a poor state of repair and prone to malfunction. An interesting question from the perspective of outside cameras would be if anyone entered the cell and if so how did they achieve it? Assuming the door was locked (which seems to be the case) it would require someone with access to keys and that's no small deal. Key allocations in secure institutions are very tight and staff cannot merely enter or leave the building without being logged in and out, typically being assigned a designated set of keys for purposes of audit trails. Those keys then do not leave the person in secure areas, typically being strapped to their belt or similar. Movement of staff between areas might be free but would still be noticed by others, so investigators would know that there had to be some involvement (witting or otherwise) from officers or their superiors, even if it were merely a case of having opened the cell door. Movies tend to make these things appear much simpler than they in reality are. James Bond kicking out ventilation grills or Bruce Willis sneaking through the sewers is by and large the stuff of Hollywood, in reality anything a scriptwriter can ream up has already been considered and factored by thousands of people spending decades designing security procedures and foul play in reality tends to be require at least some level of complicity from the inside. You can sneak rugs and mobile phones into jails, but sneaking assassins in and out undetected just isn't happening, not unless this was severely incompetently operated facility.