Okay so I arrived late to the party, but I think I can offer some clarification.
There are two known mechanisms of time dilation: special relativistic (SR) time dilation and the gravitational time dilation of general relativity (GR). The first of those is purely kinematic, i.e. involving matter in motion that a significant fraction of the speed of light. So we could talk about the time dilation associated with the hull of an anomalous vehicle either spinning or oscillating (vibrating) at relativistic speeds, but honestly that would be a bit silly, because that doesn’t seem to offer any insight into the other signature propulsion characteristics that are commonly associated with AAVs.
So that leaves us with gravitational time dilation, because that does provide us with a comprehensive understanding of the operation of these craft which was first posited by Hermann Bondi, and then developed further by Robert L. Forward and fully elucidated in the language of GR by Miguel Alcubierre (though it is worth noting that Alcubierre’s specific metric appears to be only one possible metric, and a fairly exotic one at that – nevertheless, it works mathematically). Martin Tajmar has recently expounded on this idea and his paper is freely available so we can have a look at it here:
https://pdfs.semanticscholar.org/829d/e3d5e49df0ba95e99936f6b0337da34de914.pdf
So a big part of the reason that you two gentlemen are in such intense disagreement about this subject is that the time dilation factor is only half of the equation; we really need to be looking at the entire spacetime manifold to see what’s going on with these devices.
As you can see in Tajmar’s paper (and Robert Forward’s earlier papers, which seem to be behind paywalls at this point, regrettably), the capability to create negative inertial mass is sufficient for reactionless propulsion schemes: with two equal and opposite inertial masses (one positive and one negative) a spring will suffice to generate reactionless propulsion. But we’re interested in the field propulsion model involving gravitational time dilation, so we’ll focus on that.
There are couple of points to consider here; first, a gravitational field cannot be shielded or, to the best of our knowledge at least, contained. So regardless of the mechanism utilized to generate the positive and negative gravitational poles required for a gravitational field propulsion system, that field will extend beyond the craft, and the interaction through the craft will yield the self-acceleration interaction that propels such a device. We should note that in the center of such a device, the two poles of gravitational field cancel, forming a region of zero gravitational time dilation – this is likely where the pilot and/or guiding instrumentation would be, so we don’t need to get into comparing rates of time in the interior and exterior reference frames: for all practical considerations they’re the same; the pilot is experiencing the same rate of time as the witness, unless some additional gravitational field is used which is unrelated to propulsion.
Both poles of gravitational field dilate time, but in opposite ways. The ordinary positive gravitational field like we experience here on the Earth, slows the rate f time experienced within the field, compared to an external observer. A negative, aka repulsive gravitational field, like we see with the dark energy effect in astrophysics, accelerates the rate of time within the field, relative to an external observer. But this isn’t the key factor pertaining to the question of the sonic boom, it turns out. Which should be too surprising – the magnitude of gravitational field required to dilate time by, say, an order of magnitude, would be enormous – far greater than the field intensity required to produce the kinds of dramatic accelerations that are commonly reported.
The key factor is the acceleration field itself, which is a spacetime distortion field. It turns out that either form of gravitational pole can explain the absence of sonic booms when these devices accelerate to hypersonic speeds. Paul Hill investigated this subject in significant detail in his book Unconventional Flying Objects, and others have expounded on this subject as well, including Dr. Hal Puthoff. But simply put, a repulsive gravitational field at the leading edge of an AAV would create a diffusive gradient in the atmospheric pressure ahead of the craft, preventing the localized compression of atmosphere that produces a sonic boom. And an attractive gravitational field ahead of the craft would create a gradient of compressed atmosphere ahead of the craft, like a pillow of air, which would also diffuse the compression region and also prevent a sonic boom. It’s the gradient itself, rather than its sign, which prevents the production of a sonic boom.
So it doesn’t matter how the gravitational field poles required for propulsion are produced – whether via a device inside the craft, or by the material of the hull itself; in either case the gravitational field will extend significantly beyond the craft (and drop off by the inverse cube law, because the field is dipolar in nature), thereby preventing the production of a sonic boom.