And here's one which I spotted: I think that the last full sentence at the bottom of p98 is wrong. I think the "action" they define is not an action, and I think the first couple of sentences of section 4 should be:

Let $G'$ be a subgroup of $G$. If $A'$ is a $G'$-module, we can form the $G$-module $A=Hom_{G'}(\Lambda,A')$. We give $A$ the following $G$-module structure: if $\phi\in A$,then $g.\phi$ is the homomorphism $h\mapsto\phi(hg)$. Then we have...