Item duplication on death in realm

I was playing on my realm with a full inventory. I was being rushed by a creeper while I was riding a skeleton horse and the creeper exploded and killed me as I swung an iron sword to kill it. When I respawned I still had the iron sword in my hand and when I went to retrieve my inventory I found the see iron sword amongst the items. I know it was the same sword because I only had one iron sword in my inventory when I died and the sword I respawned with and the sword I retrieved with my items had the exact same remaining durability. I was playing on my slightly internally malfunctioning Alcatel Idol 4 Android phone, however I doubt it would have much relation to the incident considering it was in realms server. If it may be applicable: We use redstone quite a bit and it occasionally causes lag and the incident occurred near loaded chunks with their entire surface area covered in lower stone slabs as a project interended to use the surface spawn cap for a mob farm.