Probably more a question for the main SE people, but why aren't all the options available to all the review queues?
I just had an answer come up in the 'low quality posts' queue that appeared to be spam - but the 'flag post' button isn't available there, only 'delete' - which doesn't have an option for 'this is spam'. Flag post is, however, available in the 'late answers' queue, but that doesn't have a delete option, which would be useful for the 'I'm having this problem, too" posts...
I don't know for sure, but never thought of it as a bug. The reason there are different things for different queues is because each queue is specific for what it's designed to do. If you had all the options available to every queue, you'd only need one queue.
I don't remember what is in each queue exactly, but will use two queues specifically. Look at the difference between the "Close Votes" and "First Posts". These two queues have distinctly different reasons for being. Therefore there shouldn't be the same selections.
I'm not an expert in the realm of what things are supposed to be, but in my approximation, this is not a bug, but a feature. If you believe it should be otherwise, I'd take your route to SE as a "feature request" and see what they have to say about it.
