Partition Pruning : We are over-pruning and this leads to wrong results

explain plan for select * from `existing_partition_pruning/lineitem_hierarchical_intstring` where (dir0=1993 or dir1='jun') and (dir0=1991 or dir1='aug' or columns[0] > 5000);
00-00    Screen
00-01      Project(*=[$0])
00-02        Project(T17¦¦*=[$0])
00-03          SelectionVectorRemover
00-04            Filter(condition=[AND(OR(=($1, 1993), =($2, 'jun')), OR(=($1, 1991), =($2, 'aug'), >(ITEM($3, 0), 5000)))])
00-05              Project(T17¦¦*=[$0], dir0=[$1], dir1=[$2], columns=[$3])
00-06                Scan(groupscan=[ParquetGroupScan [entries=[ReadEntryWithPath [path=/drill/testdata/ctas_auto_partition/existing_partition_pruning/lineitem_hierarchical_intstring/0_0_26.parquet], ReadEntryWithPath [path=/drill/testdata/ctas_auto_partition/existing_partition_pruning/lineitem_hierarchical_intstring/0_0_7.parquet]], selectionRoot=/drill/testdata/ctas_auto_partition/existing_partition_pruning/lineitem_hierarchical_intstring, numFiles=2, columns=[`*`]]])

select count(*) from tbl_nopartitions where (dir0=1993 or dir1='jun') and (dir0=1991 or dir1='aug' or columns[0] > 5000);
+---------+
| EXPR$0  |
+---------+
| 14515   |
+---------+
1 row selected (0.903 seconds)

select count(*) from `existing_partition_pruning/lineitem_hierarchical_intstring` where (dir0=1993 or dir1='jun') and (dir0=1991 or dir1='aug' or columns[0] > 5000);
+---------+
| EXPR$0  |
+---------+
| 1800    |
+---------+
1 row selected (0.49 seconds)