They have no real reason to expect someone to be here. A search of the building is in order to determine if there are any other cases within, possibly some sort of quarantine, but likely not much will happen beyond a quick search of all the rooms and accounting for all registered tenants. If we just hide ourselves somewhere without being spotted we should be fine, but we would probably have to stay there at least a few hours, possibly a few weeks... Leaving now would risk being spotted, we would basically have to blend into the crowd, and not be spotted leaving the premises...
We could probably still turn ourselves in and not get dissected. Who knows, maybe spending an eternity in confinement being studied could be fun...
Head-shots are lethal to kids.
Massive trauma is not lethal, but is somewhat debilitating to kids.
I am not sure about broken bones or muscle damage, but the poor little thing seemed to be pretty capable with a pair of arms that should at least have been heavily bruised.
We still don't know much about ourself or the process of creating zombies. Possible experiments include:
Non-lethal bites.
Injection of zombie-blood.
A transfusion of whatever is in our veins.
Zombie-juice on broken skin.
Prolonged exposure of zombie-juice to unbroken skin.
Ingestion of zombie-flesh.
Inhalation of zombie-flesh.
All of the above applied to cats, dogs, horses, cattle, ostriches, starlings, ravens, pigs, snakes, octopuses, mushrooms, trees, bacterial cultures, rocks, rivers, magma, Earth, Sol, Milky Way, Big Bang, The Ether, The gods, The author, tropes...