GIven that you describe him as having a scared look and then peeing in the hallway, I'm thinking that this caused in part by his attempt to be submissive, and with you scolding/punishing him you are just making the entire behavior worse.
Dogs often show submission by urinating. You can see this is interactions between dogs, or in dogs that are submissive and greet someone. They will dribble urine or sometimes even let go quite a bit. This is NORMAL and the best thing to do is to keep all encounters happy and positive, with zero punishment or actions that the puppy would consider punishment (like saying "OH NO!" or pulling him away or making unhappy noises). The best thing is to ignore it. Honestly. Anything else just increases his desire to be submissive, which increases the likelihood that he's going to continue to pee.
You're asking a puppy to hold his bladder for a long trip to the potty place. This is kind of unreasonable. When his bladder is full anyway, walking him stimulates it and he will need to go more quickly than he can hold when you're talking a trip down a hall, waiting for an elevator, and then down the elevator. You may want to pick him up and talk happily to him while you walk out your door to the elevator, and not put him down until he gets to where you want him to pee. Of course, this is not a long-term solution but it will hopefully help him learn that the peeing isn't to happen until he's all the way out. After a few days, you might carry him to the elevator, walk in and set him down while you hum a little tune, and then walk him out of the elevator to where he potties (using lots of praise when he DOES potty in the right place). And once he's got that down, you can carry him to the elevator, put him down before the door opens and walk him in and then out to the potty area. You just gradually backtrack until he can handle the entire distance to the potty area without having to go.
You also need to do some thorough cleaning in the hallway where he's already peed. Try to get that scent up. And if you take him out on a leash into the hallway and he pees, you just turn your head away and hum a little tune and walk him to the elevator like nothing happened. Then when you come back in, you put him away and then go out and clean the area again. He needs to gain confidence as well as physical control before he can walk all the way to the potty area without an accident.
He's just a baby - please enjoy him and don't get too upset when he does something like this. He truly doesn't understand and is only doing what is natural, and when you get frustrated and upset at him it makes him only more likely to do things you don't like.
Good luck -
Melanie and the gang in Alaska