showToast displays wrong string in simulator

I added a showToast to my app to help me debugging. I only use showToast in this one place in my app:

        if (WatchUi has :showToast) {
            WatchUi.showToast("onPhone", null);
        }

and a little but "later" in the code I log something:

        log("deleteTrack");

the string "deleteTrack" only appears in this one place in my code.

log is basically calling:

function log(msg as String) as Void {
    System.println(msg);
}

But for some reason this is what I see in the simulator on fr955:

Interesting. Looks like some compiler and/or simulator memory reference bug.

What's even more interesting is if I add a breakpoint somewhere after the call to showToast and before the use of the "deleteTrack" string then I see the correct string being displayed.