Goofs

The alpine butterfly knot is not particularly complicated, or hard to tie. It is however one of the most stupid choices for a fake hanging, it can't be tightened, so an actual hanging would be impossible, and since limp bodies won't keep their heads down, so don't stay dangling from loose loops, the victim would have fallen out.

Basic common sense says no-one can be 1 of 3 black kids in an all white school. If there are black kids, it's not all white. The word is "predominantly", or just "mostly".

Maura offers green tea as a substitute for coffee because it only has 15mg of caffeine, so it's much healthier. Except, and cup of green tea contains 30-40mg of caffeine. While that is less than half the caffeine of a cup of coffee (80-100 avg), it's nearly 4 times what Maura said, and 3-4 times the caffeine content of black tea, which contains 10mg per cup. Also, and couple of cups of coffee a day isn't harmful, it's only drinking it to excess (like literally everything humans eat or drink) that's unhealthy, but depriving people of the caffeine they're used to can cause all sorts of withdrawal symptoms.

Supposedly the victim was writing on an Underwood Number 5 typewriter, but one of the many reasons the No5 was the archetype of typewriters was that it wasn't a "blind writer", ie, you could see what you were writing without raising the carriage (basically the letters hit the paper at the front, not underneath).

The new "healthy" cafe would have caused a majority of the department to be off sick, or just incapable of doing their jobs. Caffeine withdrawal causes debilitating headaches, irritability, depression, difficulty concentrating, fever, fatigue, and flu-like symptoms. And that's just swapping out the drinks, add in the new menu, that no-one's digestive system is ready for, and the program would cause a catastrophe.

The typewriter was almost certainly not from the 30s. Underwood produced the Number 5 from 1900 to 1931/early 32. Since there's no way to date and No5, the 1930s was almost the worst decade to pick; only picking a decade when it wasn't made at all could have been worse.

Dr. Isles says the victim was "hung", when humans are "hanged" ("clothes are hung" is the way it's taught in schools). Maura should know the difference, and would normally have corrected anyone using the wrong word.

That's not what steampunk or punk mean, and there's no such thing as a "Steampunker". Steampunk has absolutely nothing to do with punk fashion. (Depending who you ask) It's either a parallel reality where Victorians had futuristic technology, or just what the Victorian era would have been like if they'd had more modern technology, powered by steam. (So that laptop wasn't even close.) Punk is about rebelling: rebellious music, wild hair, dressing like you fell through a shredder and patched the holes with zips and pins; and put more pins through your face. Steampunk fashion is "what happened when goths discovered brown". And someone who is into Steampunk fashion and lifestyle is a steampunk. Just like someone who is into Punk fashion and lifestyle is a punk.