SELECT INTO OUTFILE query succeeds even if backed fails

query SELECT * INTO OUTFILE '/tmp/t1.csv' FROM t1; does not generate error in case if backend fails to execute this query

steps to reproduce:
1. create /tmp/t1.csv file on all backend nodes
2. execute SELECT * INTO OUTFILE '/tmp/t1.csv' FROM t1; against RWSplit router (should be checked also with ReadConn router)
3. check error log
Error : Failed to execute select * into outfile '/tmp/t1.csv' from in 192.168.122.119:3306. HY000 File '/tmp/t1.csv' already exists

Expected result: step 2 fails with error
Actual result: no error, t1.csv does not contain info from DB