Completely agree with Sven and a couple of others. It may not look like we're taking avoiding action but to fly over at 250ft is, probably, a better compromise than putting down a whole load of bladeslap at 100ft in an attempt to go round the rider. A gentle (ie, no extra power) climb just takes the noise higher and disperses it. It would be interesting to hear a horse rider's view on this.
On hi visibility, there is no doubt, it stands out a mile provided that:
a. The rider is not hidden (although it still helps through some 'thinner' trees)
b. The rider and horse wear the stuff. A thin vest doesn't really work and the rider needs to wear a full jacket. In addition, the horse should wear a hi-viz cover. Anything less compromises the positive results of the trial. I know that isn't popular with a lot of riders as they want to look part of the country in their browns and greens but it's a fact of life, if only so that they don't get run down by a car.
One final point: The trial was only for helicopters and as a direct result of the Bell case. I'm not sure how much the FJ fraternity can take from the results of the trial but there must be some postitives. The RW have had to change an awful lot of their procedures and this has increased their workload when planning a low-level sortie. Isn't it only fair that the horse-riding society meets us halfway?