Freestanding Tub Drain Connection

Finishing up a bathroom remodel. There’s a clawfoot tub with an exposed drain into the floor. We flagged an issue with the finish work where the floor and tub drain meet. While fixing that issue, we believe an even bigger issue was identified with the exposed pipes connection to the pipe in the floor. It looks like the plumber just set the brass pipe inside the PVC without any sort of connection. Our contractor flagged the issue to the plumbers PM, who initially indicated it was wrong and they would need to get into the floor through the room below to fix it. I’m now being told by my contractor that, “According to the people that installed it, they glued and siliconed the copper pipe to the PVC.” This still doesn’t seem right to me, considering I can wiggle the pipe. Our contractor said he’s planning to verify with them on site tomorrow. I’d love to be prepared speak confidently about what’s right or not and what needs to be done to fix it.

Attached a couple photos for reference. I’m no plumber, but it seems like there should be some sort of coupling or something so it doesn’t leak if there’s a clog…