Thanks for reporting this. In the current build a contract only closes once the last piece is hauled away and the decon crew has scrubbed the street clean. A new firm starts with one crew, so there can be a long wait after the body is gone with nothing left to click.
What did the screen show when it stuck? Was there still dirt on the street with a crew moving over it, or had everything stopped? Either way that wait should be obvious and it isn't, so we're treating it as a bug. We'll reply here when a fix is live.