Well, I must say that in 25 years I've never encountered a DM like that.
I don't mind a longwinded DM, and at times I've felt like the long winded DM and even asked my PC's if they thought my descriptions were getting to florid, but they seemed to like it - or at least they encouraged me to continue. And I don't mind not picking up the dice much. Picking up the dice is not really part of role-playing, its how you arbitrate propositions that have interesting consequences if they fail.
But, if the description is accurate the DM is doing something that no good DM should do - telling the player what his character does or how the character responds. That is not to be tolerated except in cases where something like a charm is influencing the character.
There is nothing 'primitive' or 'old school' about that sort of DMing.
So, reasonable and good:
"DM: "29? WOW. You see the Assassin almost turn invisible. One second he is there and one second he is gone. Even though the Artificer has gone after him, she has difficulty finding him and just has to head in the general direction of the camp and hope she finds him. Assassin, you hear the sound of water crashing into a pool and voices up ahead. You hear someone say 'Where do you put my shirt?' and some arguing. Up ahead, the trees are thick and hard to see through. Keep in mind that these are primeval forests, not the forests of today."
But bad:
"You proceed past the men bathing in the pool nearby, the sound of the waterfall masking your progress until you reach the camp."
The DM needs to put a decision point here. You've provided a new set of choices to the PC, and now you need to know essentially, "Do you want to continue on to the main camp or turn aside and investigate the pool where the voices are coming from?" As a DM you don't know that the PC 'proceeds past the men bathing in the pool nearby' until the player tells you that you do.
Aside from forgetting who can see what in a divided party, good:
"There is lots of noise in the camp so it easily covers you as you get closer. In the camp you see a couple of people. One, the Fighter recognizes (The fighter couldn't even see the camp from where he was standing, by the way) as Bob (can't remember the name).
But bad:
He is the evil slaver you met in your travels before. He is a vile, wicked man who traffics in flesh and mistreats his slaves. As you watch this man walk towards a wagon that is covered, obviously to prevent people from noticing that it contains slaves.
This isn't nearly as big of a flaw as telling the player what the character does (I'd be tempted to find an excuse to leave early if too much of that happened), but its not really polished DMing because its telling instead of showing. Don't tell someone how vile and evil an NPC is, showthem. Don't explain why things are as they are, let the character decide for themselves or ask. Your job is to show 'what, who, when, where', and to leave 'how' and 'why' for the PC to figure out.
Bad:
You are aware that she makes way more noise than you and you quickly tell her to be quiet.
This one is particularly irritating, because its not only depriving the player of a choice but its depriving a player of the oppurtunity to role play. What really should be said here is something like, "Jane finds you. She's making entirely too much noice.", and leave it to the players to create the scene.
Bad:
What we have here is a choice. You have Good people amongst you and they cannot allow these slavers to continue their work. But as you look, you can see that the woman you are looking for is not amongst the camp. The monk suddenly appears beside you, just as silent as you are. He says that if you stop to deal with the camp, all hope is lost in finding this woman he is looking for. But if you choose to do something about it, he will understand. He cannot stand slavers either. If he needs to trade the life of one person for the lives of many, he will make that trade. But it is up to you.
Uggg... uggg... I can't say how bad that is. I really hope that summation isn't doing it justice, because I can't imagine playing like that.
In all fairness, it also doesn't sound to me like the player's are what I'd call particularly skilled either as it seems to me from the description that there was alot of attempts to resolve in game situations out of character and using meta-language, and the DM found himself doing alot of translation to explain things in in-game language.