ACID IOW implemented using base may delete too much data

Suppose we have a table with delta_0 insert data.
Txn 1 starts an insert into delta_1.
Txn 2 starts an IOW into base_2.
Txn 2 commits.
Txn 1 commits after txn 2 but its results would be invisible.

Txn 2 deletes rows committed by txn 1 that according to standard ACID semantics it could have never observed and affected; this sequence of events is only possible under read-uncommitted isolation level (so, 2 deletes rows written by 1 before 1 commits them).
This is if we look at IOW as transactional delete+insert. Otherwise we are just saying IOW performs "semi"-transactional delete.

If 1 ran an update on rows instead of an insert, and 2 still ran an IOW/delete, row lock conflict (or equivalent) should cause one of them to fail.