I bet a lot of what the paramedic friend types is repetitive and industry specific. Could speed things up with some macros/text expander type of functionality. The multi presses reminds me a lot text messaging back before smartphones. Most kids could type quickly without really looking and using just a thumb.
In reality, laptops are quite common on ambulances, and get used during many (even most) "routine" calls. The issue with note taking is with more critical patients, and there are a variety of reasons why a notepad and (cheap, disposable) pen are the best solution. The biggest reason is because I can use them with a gloved (potentially contaminated) hand and not worry about how to decontaminate them, since I'll just throw them out. This device has many of the same failure modes as the laptop (namely, it would be impossible to clean).
A lot of medics will skip the pad and just write on the non-dominant gloved hand. Personally, my favorite technique during especially busy calls is to put a strip of 2in/5cm wide cloth medical tape on my thigh and just write on my leg.
But "practicality" wasn't really the point here...