The standard text discussion of the equivalence principle and the bending of light rays goes like this. We, as observers watch a glass elevator ascending. A light beam is fired from left to right. The acceleration of the elevator causes the light beam to curve downward. Since the elevator passengers can't discern the difference between an acceleration and a (uniform) gravitational field, ergo, a gravitational field bends a light ray.
Fine, but consider the standard text derivation of time dilation---which posits that the light beam would be carried along with the elevator. Here, of course, the argument assumes inertial frames so the elevator is rising at a constant rate.
Now consider this. Suppose an elevator passenger affixes a small laser to the left hand elevator wall at precisely its midpoint and focuses it on a point midway up the right hand wall. Where do we "stationary" observers outside the elevator see the ray hit the right hand wall: at its midpoint, above it, or below it? If we buy the equivalence principle argument it will clearly be below (even if the elevator speed is constant) because of the upward movement of the elevator. On the other hand, the midpoint is a physical thing which can be identified by, say, a paint blob---so one could reason that the light beam should hit the right hand wall at its midpoint.
I don't think simultaneity issues enter the picture here. The only issue is where does the light beam strike the right hand wall?