You can reassign the pending task w/ sql.
1. Find the userid of the deleted person
Located in the cf_user_snapshot table. The id you are looking for is column "user_id"
2. Find the userid of the person you wish to assign it to
Located in the cf_user_snapshot table. The id you are looking for is column "user_id"
3. Find the current task assigned to the old user
One row is located in cf_bp_worker_instnc_to_resume, column "owner_snapshot_id"
Another row is located in cf_bp_instance_approvers, column "user_snapshot_id"
"Owner_snapshot_id" and "user_snapshot_id" will have the same value along with a matching "resume_id". An entry is made per task per user.
4. Update the current task to the new user
Change the user_id to the new user in both spots mentioned in step 3.
The task will now show up in the inbox of the new user instead of the old user and future history will display the approval as such.
*Note, directly modifying the underlying SQL is a last resort option as it is an supported area of Laserfiche, you are relying on myself (a regular user), who did this once before, so please proceed with caution.