The author again falls into the strong vs. weak, and static vs. dynamic trap without a solid understanding of the terminology. As per usual the widespread misuse of the terms has made them useless. It is worth reading from a more rigorous source, such as Luca Cardelli: http://lucacardelli.name/Papers/OnUnderstanding.A4.pdf. Or ignoring them as Benjamin Pierce says, "I spent a few weeks... trying to sort out the terminology of "strongly typed," "statically typed," "safe," etc., and found it amazingly difficult.... The usage of these terms is so various as to render them almost useless.".