File protection on create

Is the following expected behavior?

With normal default protections set:

$ say := write sys$output
$ say f$env("protection")
SYSTEM=RWED, OWNER=RWED, GROUP=RE, WORLD
$ perl -e "open(F,'>1.1'); print F 1; close F;"
$ dir/sec 1.1

Directory USERS:[BERRYMAN]

1.1;1                [BERRYMAN]                       (RWD,RWD,R,)

However, change the owner default to read-only and:

$ set prot=ow:re/def
$ say f$env("protection")
SYSTEM=RWED, OWNER=RE, GROUP=RE, WORLD
$ perl -e "open(F,'>1.1'); print F 1; close F;"
$ dir/sec 1.1

Directory USERS:[BERRYMAN]

1.1;1                [BERRYMAN]                       (R,R,R,)

Why is the file being created with system only having Read access when the owner default is set to read?

Mark Berryman