This is possible with some data retrieval tweaks.
tb_process_instance table has a column named 'status' which shows you various status of the process isntance including 'stalled'.
tb_task table contains all the tasks created. You can filter the items based on given process id (column name is process_instance_id).
retrieve the largest value of id column from within the filtered list.
There is a column named completed_by which contains the oid of the user who completed the task. This is the recent user who worked on the stalled process.
Note: If you would like to retrieve the user name/email or other info, get details from EDCPRINCIPALUSERENTITY table.
Nith