Performance of Query where time captured from SP statement completed differs by large from RPC completed
Generally speaking rpc_completed includes network time, while sp_statement_completed does not.  This is very likely the case for your query, since it only returns one row.

So one explanation is the extra time is spent sending data over the network to the client.

You could try measuring wait statistics for this query to confirm there are 24 seconds of ASYNC_NETWORK_IO waits that explain the difference.  

If the server has SSMS installed, you could remote desktop into it and run the query there, which should have very little network wait time.  In which case you'd see very little difference in the time on those two events for this statement.