You would be wrong. Try adding a string and number together. That's a type error. Unlike in JS or C, where a lot of these conversions are implicit and only warn if anything.
Python determines the types at runtime, but it is very clear about what few operations you're allowed to do on any given set of types.
What that article calls "dynamically typed" is commonly referred to as "untyped" in PL research.
The program '1 + "2"' is a perfectly valid python program with well defined behavior (it signals a TypeError). This demonstrates that you can in fact add integers to strings in python. Of course whether or not you can add integers to strings is completely orthogonal to whether or not a language is typed. Both typed and untyped languages may overload the addition operator.
I wouldn't call C untyped because implicit conversions happen all the times. It's just that it assumes that since you declare your variables with a type, when you assign them, you know what is going to happen.
