I want to know did they confiscate the bit and hay ball as evidence? Do any photos exist? Clearly, tying fibrous foodstuffs to the bit is against the spirit of the rules - but feeding a bit of sugar to encourage salivation isn't a shooting offense, and letting a horse graze a bit is a common endurance rider means of getting pulse and respiration down - probably more eventers should try it before dressage... ( )
I would guess that the right bundle of hay could relax a horse's jaw, could make it harder for a horse to draw his tongue back and possibly put it over the bit, could mute raucous bit chewing and clanking. Interesting!
My thoughts are you do not try something new like that at a 4* so my guess is that it has been tested before.
Riders have often used various things in the past. The most common is to offer a mint before going in to try and keep the mouth accepting. The worst I have heard of is using saddle soap to try and stop the teeth grinding. I heard that it bought the horse out in ulcers.
Before i ride somtimes i give my horse an apple, or mint. Is that bad? Would I get stopped at a competition if i did this?
and letting a horse graze a bit is a common endurance rider means of getting pulse and respiration down - probably more eventers should try it before dressage... ( )
Just in the COTH-y interest of disseminating good information across disciplines, that's not actually why Endurance horses get to eat. Eating technically raises pulse (I don't know whether it measurably affects respiration as that's rarely taken anymore). The practical effect may just be that the HR does not lower quite as quickly. Horses whose HRs are already down or close to are generally offered food immediately. Eating while working has other important benefits (ulcers, colic, stamina, blood sugar spikes, attitude/barn sourness etc) and I absolutely think Eventers should take advantage of them. I've talked to Eventers about this before and one person told me she has seen mounted horses grazing while waiting to go XC at bigger events. I'm not sure why it's not more common, or maybe it's becoming so?
As for the hay ball...that's freaking hilarious. I wish we had a picture and a window into the rider's thoughts at the moment she knew she would be caught ("Oh no! They're going to find the hay ball! Act surprised.")