In a way it is but I'm unsure what the correct way of treating this situation should be.
When using the trace function in Codewarrior it creates a buffer in RAM to store the trace information. It also includes an zeroed region in the binary file image to initialise the buffer to zero when the image is loaded into the target. This situation is accepted by USBDM when working within Codewarrior since it makes some sense to download 'stuff' to RAM when debugging a target.
The USBDM stand-alone programmer produces an error because it doesn't make sense to 'program' something to RAM. If your program image contains data destined to RAM then it would (usually) indicate that there is a mistake in the memory map since such data would be lost when the target is reset. It seems sensible to flag this as an error.
Basically - You should turn off the trace function when producing a final image for production. This is sensible in any case since tracing should not (normally) be in use in the production target.
When I have time I will consider adding an option to the programmer to ignore writes to RAM but I really think this is of little value.