robot framework: exception handling

Is it possible to handle exceptions from the test case? I have 2 kinds of failure I want to track: a test failed to run, and a test ran but received the wrong output. If I need to raise an exception to fail my test, how can I distinguish between the two failure types? So say I have the following:

*** Test Cases ***
Case 1
    Login            1.2.3.4    user    pass
    Check Log For    this log line

If I can't log in, then the Login Keyword would raise an ExecutionError. If the log file doesn't exist, I would also get an ExecutionError. But if the log file does exist and the line isn't in the log, I should get an OutputError.

I may want to immediately fail the test on an ExecutionError, since it means my test did not run and there is some issue that needs to be fixed in the environment or with the test case. But on an OutputError, I may want to continue the test. It may only refer to a single piece of output and the test may be valuable to continue to check the rest of the output.

How can this be done?