Tub Spout Not Flush

I recently had a contractor replace my tiled tub surround with cultured marble. He did a great job but did not reattach the plumbing fixtures. I did not think this was a big deal and thought I could easily do it myself (I am not a plumber). Everything was a no brainer with the exception of 1 problem I encountered

When I reattached the tub spout (threaded type) I noticed that as I tighten it, it is not flush to the wall. This is because there is some play in the pipe that the spout threads on to (which I can't access). The more I tighten, the larger the upward angle on the tub spout.

The top of the spout is flush to the wall, there is a small gap (1/16 to 1/8 inch) at the bottom of the spout. Can I just caulk this or is there something else I should be doing to address this?

Why not call him back up and inform him of this problem. He has probably dealt with this type of problem before and can readily fix it.

I would be concerned about water getting down in there where their is a gap.

Best practice (IMHO) would be to always use a dog-eared 'el' in the wall and anchor that end to some solid blocking. Then, assuming you got it perpendicular with the wall, there'd be a nice solid connection to mate the spout with. Leaving it unanchored spells amateur or cost cutting to me.

The problem is that the pipe is not secured inside the wall, and at this stage it may be very difficult to correct the problem. As you tighten the spout, it pulls the pipe outward, and that makes it tilt upwards. Your only option may be to caulk it, but leave an opening at the bottom so any water that does get behind the spout has a way to escape.

The best possible option would be to open up the wall to access the valve and slide a block between the spout and wall to pull the spout closer and flush with the tub wall.