Pairwise but not mutual independence

Two fair coins $S_1$ and $S_2$ are tossed independently once. Let the events $E$, $F$ and $G$ be defined as follows: $E$: Head appears on $S_1$; $F$: Head appears on $S_2$; $G$: The same outcome (head or tail) appears on both $S_1$ and $S_2$. Then which of the following statements is NOT correct?