It definitely drops the last word for the cell phone app. I often talk using the desktop client to someone using the cell phone app, and every last word of a sentence she says seems dropped
We use the desktop client and our group often has problems with words being dropped not only at the end but also in the middle of someone talking if they're using voice activation. :-/
It's usually specific users whose words get dropped, maybe their activation threshold is just low enough. But still, seems to me like this should not happen, especially in the middle of sentences, since the beginning of the sentence is recorded just fine.