Quote replacement using '!' as the replacement character results in error  "ORA-00911: invalid (4303675)

Ran the following sql statement in the editor:

"select q'!I love John's Place too!!' from dual;"

If it's run using Execute Statement (F9), or in sql*plus, the query runs OK

If it's run using Execuate as Script  (F5) it errors out with

"ORA-00911: invalid character"

Parser error

WORKAROUND

Use another character or square brackets as quote replacement character if string contains an exclamation point (!) at the end.
e.g. 

"select q'[I love John's Place too!]' from dual;"

STATUS

Waiting for fix in a future release of Toad for Oracle