You chase down a hooded punk, and you end up wrongly accusing some big tough guy instead.
Proposal
If someone attacks/aims/grabs a shrouded person, perhaps the game should roll a random number to determine whether their target is the intended Player Character or not. If the roll result is not the intended Player Character, then a dynamically generated NPC is summoned and the attacker's attack is then redirected towards that summoned NPC.
This summoned NPC could be as weak as an immy, or as strong as Seven Ecks. This way, attacking shrouded people is a very risky and perhaps even a non-rewarding thing to do if the summoned npc is itemless.
And perhaps for every room in the game, there could be a population value to determine how many shrouded people there could IC-ly be, and use that to determine how likely it is for an NPC to be rolled as the result. In the case of topside, the value for shrouded people should be zero since there shouldn't be shrouded people in topside in the first place. And thus, attacking a shrouded person topside will always hit the Player Character.
And let's not use skills or stats to determine the roll. Let's just make it so that it's always 80% or more likely that your attack against a shrouded person will spawn an NPC rather than actually successfully targetting the intended Player Character.
After the summoned NPC is out of combat long enough, it will disappear.
This way, we can sort of let the game help enforce the philosophy that we really don't know who the shrouded person is.