It should give a message if you weren't able to pick up everything. I've seen it a few times myself. And 'g','g' also brings up the menu that mumra is referring to and does make going through a big pile much easier. I should have been more clear: the interactive prompt confirms if you pick up an it...

This is a little thing that's been bothering me when picking up items out of a pile through the interactive prompt (a single press of 'g'). There's no feedback at the end of the process if, as is usually the case for me, you don't pick up the final item. This is the only example I run into regularly...