Possible Bug or am I just missing something?

So my opponent swung with the Dredger and a Temple Scribe. I blocked the Scribe and killed it, assuming it would go to my void so that I reanimate it. Instead, he played it again with Memory Dredger's trigger. Shouldn't it have gone to my void instead, making him unable to play it again via Memory Dredger, or am I missing something? Thanks.