Reloading a small-frame revolver during a fight in the world of civilian self-defense is similar to the unicorn: you can picture it in your mind based on science fiction writing but you can’t find it in the wild. Still, having a full command of your defensive tools is a good thing, so if you carry a revolver, even occasionally, being able to reload it is in order.
In regard to using a speedloader there are many overall techniques that shooters employ. One of the elements involved in this skillset is whether to lift the speed loader up and away from the cylinder of the gun after the rounds fall into the charging holes, or to simply let go of the speedloader and let it fall away as the cylinder of the gun is pushed closed. The argument to pull the loader up and away states that the speedloader can often bind on one or more of the cartridges, thus getting stuck between the cylinder and gun when trying to close the action. The argument to simply let go of the speedloader is that it is simply faster, and the action of pulling the speedloader away can actually cause cartridges to not seat in the holes anyway.
So, what is the best option? I have worked with enough variables to confidently say that it depends on the speedloader/gun combination, as well as the other elements of your technique. For example, when using a Safariland Comp I speedloader with my Ruger SP101 (a gun I used and carried for a while, but no longer do) I found that the speedloader would often bind if I did not pull it away after releasing the rounds. This is a common issue when reloading small-frame revolvers as there is simply limited real-estate between the cylinder and the frame of the gun. The slightest miss-alignment results in a bound speedloader. Speedloaders like the Safariland Comp I and the ubiquitous HKS are rather wide and bulky and they provide limited room when used on small guns like LCRs, SP101s, or J Frames.
However, my experience with this issue has proven the exact opposite when using a 5 Star speedloader with my Ruger LCR. In this case, I find that the smaller profile of the 5 Star does not cause the issue of binding against the frame of the gun or the grip, and pulling the speedloader back away from the cylinder can, in itself, cause a round or two to fall out if done pre-maturely. Since the design of this speedloader eliminates the binding issue, just letting the speedloader go after twisting the release nob results in a consistent and clean reload.
Conclusion: it depends on your gear and the rest of your technique and you need to experiment to know for sure. I would say that, as a general principle, pulling the speedloader away is safer as it will avoid binding, a common issue with small revolvers and most speedloaders. However, depending on your setup, simply releasing the speedloader and letting it fall away may work better. To know for sure, bust out the snap caps and try both.