If it is a "non-sanctioned" YMCA meet, then judge can do whatever the judge wants. That's the non-sanctioned part, or should be. Unless you just mean "not USAG" and there's a YMCA code of points or rulebook that you must follow. If it's truly non-sanctioned, then the USAG guidelines wouldn't apply because it's not a USAG meet. They'll still be followed because that's what everyone knows. But, modifications can be made (and are, often, if you look closely). Just try and catch the judge/meet ref/meet director before the meet starts so the judge can decide if she wants to make that not a deduction for everyone, (explain the situation, the tall gymnast, the low high bar, etc.) and possibly even make an announcement at the coaches' meeting. As long as everyone is aware of the privilege before the meet begins, so everyone who would like to take advantage of that option knows it is there, that's the luxury of not being sanctioned--accommodations can be made.