{
    "block": "contenttweaker:hot_iron_ingot",
    "setblock": {"block": "minecraft:air"},
    "sethelditem": {"item": "contenttweaker:hot_iron_ingot"}
    }

On the placeEvent json this bit of code allows the item to look as if it was being returned to your hand. The problem is that it only works correctly if its not returning the same item. If you place stone and return dirt to your hand, there wont be an issue. If you place stone and return stone to your hand, the stone will be invisible, yet still here. Only way to fix is to open your inventory and left click the item out of the slot, then it becomes visible once again.

I know this action can be done similarly in simpler ways. The way I'm doing it is necessary ,because it compliments a chain of actions that would not be possible if done any other way.

I could probably work something out. Just thought I'd let you know this seems to be an issue. Not sure if it's worth fixing if it might break something.