On a Fedora 21 system under Bash, trying to execute a non-existing command starting with a period results in a return to the prompt without any error message:

$ .thisfiledoesnotexist
$ 

More specifically, it silently returns to the prompt with a failure code:

$ if .thisfiledoesnotexist ; then echo OK; else echo KO; fi
KO
$

Under bash --norc, the same command fails properly:

$ bash --norc
bash-4.3$ .thisfiledoesnotexist
bash: .thisfiledoesnotexist: command not found
bash-4.3$ exit
exit
$

The cause can be narrowed down to PackageKit:

$ bash --norc
bash-4.3$ .thisfiledoesnotexist
bash: .thisfiledoesnotexist: command not found
bash-4.3$ source /etc/profile.d/PackageKit.sh 
bash-4.3$ .thisfiledoesnotexist
bash-4.3$ exit
exit
$