No wait on death spawning (Yorrick+Sion Combo)

So I noticed something that happened several games in a row the other day and just had a game today and found it's not something that just freakishly happened, but happens every time. When Yorrick ulted me and I ran in to clean up and tank as Sion, I died then came back as his shamble. I then died after another kill in that mode, then popped my passive. I then proceeded to smack them away from their tower preventing them from protecting it....

All good so far, but then after all that I spawn instantly back at base with no wait. Happened every time. Just thought I'd mention it.