RootShell.exists(filename) produces unexpected return value

[lbdroid]

Testing for the existence of a file at /data/ssh/sshd_config
file mode is 600 owned by root.root, directory mode /data/ssh is 700 owned by root.root, directory mode /data is 771 owned by system.system.

First run of RootShell.exists("/data/ssh/sshd_config") returns boolean "true". Subsequent runs are more or less random. Typically inverting each run, but occasionally producing the same result back to back.