Using Heimdall 1.4.0 on Mavericks on a Galaxy S4 SGH-I337 to flash CWM, I get:

> sudo heimdall flash --RECOVERY
> recovery-clockwork-touch-6.0.4.7-jflteatt.img --no-reboot Password:
> Heimdall v1.4.0
> 
> Copyright (c) 2010-2013, Benjamin Dobell, Glass Echidna
> http://www.glassechidna.com.au/
> 
> This software is provided free of charge. Copying and redistribution
> is encouraged.
> 
> If you appreciate this software and you would like to support future
> development please consider donating:
> http://www.glassechidna.com.au/donate/
> 
> Initialising connection... Detecting device... Claiming interface...
> Setting up interface...
> 
> Initialising protocol... Protocol initialisation successful.
> 
> Beginning session...
> 
> Some devices may take up to 2 minutes to respond. Please be patient!
> 
> Session begun.
> 
> Downloading device's PIT file... PIT file download successful.
> 
> Uploading RECOVERY 100% ERROR: Failed to confirm end of file transfer
> sequence! ERROR: RECOVERY upload failed!
> 
> Ending session... Releasing device interface...

Aware of the response, but it seems to have been triggered by the RC1 version of heimdall.
http://android.stackexchange.com/questions/51062/heimdall-errors-error-failed-to-confirm-end-of-file-transfer-sequence

I'm directly connected with no USB cable.