Workitem lock ignored when workflow logically deleted/completed by admin

[yegorm]

Dear all,
I found that workflow instance can be logically deleted when a
(sub)workitem is locked.
No exception is thrown. As a result, All the workitems except one
become 'CANCELLED", but the workitem in question remains 'STARTED'.
Also the workitem is visible in the user's incoming folder , but fails
to open with an error message. RSWWERRE doesn't seem to correct the
situation also.

There is a similar problem if you try to complete a workflow (through SWIA).

Did you notice this? Is it an error, or, probably, enqueue checks are
omitted for the sake of performance?
Or am I supposed to lock the workitems manually before (I saw there is
a button for that!) ?
I looked for an OSS note on this subject, but didn't find any. Did you?

Thank you in advance.

(we are running ERP2005)
Best regards,
Egor Malov