These are patches to the LGPL'd components they use, not Sparrow itself, right? (The LGPL specifically requires that you only release your modifications to the library, not your own code.) The only interesting things are some images, and some patch files inside lib/ -- nothing appears to be Sparrow's own source code.
It looks like they also toss in some compiled versions of Sparrow-proprietary code for debugging reasons, which I _think_ explains their incongruous licensing terms, but they're still strange.
The LGPL requires you, if you static ally link against such libraries, to release all of the rest of the build environment required to rebuild a working program from changed LGPL components; this involves releasing binary objects.
It looks like they also toss in some compiled versions of Sparrow-proprietary code for debugging reasons, which I _think_ explains their incongruous licensing terms, but they're still strange.