This is part of the reason it took me a while to figure it out; until I had the time to really trace it through I'd see that it didn't give any errors and assume that it was working. Once I got on the right track I made a custom action with nothing but

set temp to read (the/path/to/theFile as alias) 
display dialog "foo"

and my dialog was never shown, but Remote Buddy still said "execution succeeded". Not that I'm using a wide variety of commands—or even extremely complex structure—but, for what it's worth, this is the only script that hasn't executed as expected.

-Dave