This is now fixed and I've already pushed a snapshot build (1.0.2.BUILD-SNAPSHOT) includes the fix.
I also spent some time looking into how to get rate limit details for this particular case. As you noted RateLimitStatus doesn't include this information, but that's because Twitter doesn't return any useful information in this particular case. Even though I'm getting this error, the "account/rate_limit_status" endpoint indicates that I have not yet exceeded the rate limit. I also examined the response headers, hoping to find some useful information there that might indicate how long before the limit is cleared, but I could find no such information in the headers.
It's unfortunate that Twitter doesn't seem to give any clues regarding the status of this particular rate limit, as that information would (at very least) be useful in documentation or possibly as data attached to the RateLimitExceededException.
If you discover a way to get stats on this kind of rate limit, please let me know and I'll see if I can work it in.
Spring Social Project Lead