This kind of thinking is harmfully simplistic. When you rely on rules of thumb ("this sort of thing should go slowly") to make public health decisions, you are going to harm people.

In the US, we suffer from an insane degree of regulatory medical conservatism. No one else in the world takes as long to approve life-saving medications as the FDA, and this is not rational; it's a reflexive political reaction to the Thalidomide disaster that isn't grounded in sound reason or statistics.

Here is an extensively cited analysis demonstrating that the FDA's extreme standards kill vastly more people than they save.

http://www.fdareview.org/05_harm.php

This isn't an inevitable problem; medical regulatory bodies like the EMA are much closer to the optimal level of caution.