[Bug?] Decompiled code doesn't compile

Hi List,
         I've been doing some tests with CompiledMethods and by chance
found out that in some cases the decompiled code can't be compiled back.
The problem is that the decompiled code ends with something like:

        ...
        ^t4.
        ^nil

I don't know if this applies as a bug but I thought it was worth
reporting it. The "offending" methods I found in my image (7.4.1) are:

SmalltalkWorkbench class>>promptForSelector:for:
CompiledMethod Store.UISettings class>>methodPlacementInitialize
CompiledMethod Store.UISettings class>>datumPlacementInitialize

--
Cheers,
         Andrés