I have had this happen a lot. If it's a big huge gush of a flood all at once and the crotch is snug against your tummy, I find that most wool will wick it through with the compression onto your shirt. It kind of stinks, but with all that pressure and if they pee one hard burst, the entire area of the diaper doesn't have a chance to absorb it and only one small spot of the diaper gets oversaturated and then it just goes right on going through the wool and onto yyou! Ugh. That's where adding a doubler helps more than anything. A nice thick hemp doubler maybe even folded in half and placed right in that wet zone where the stream hits initially will do wonders in helping the outside of the fitted not become soooooo over saturated that suddenly the wool has to hold back a river, kwim? Then the diaper just gets damp on the outside and wool can keep that in, no problem. Or try a wool liner, just a thin felted piece of wool laid on the outsdie of the diaper, between dipe and cover, or laid underneath a thick-ish soaker pad, if the diaper body itself is a thinnish shell, so you don't really *need* those shell layers to do much work, it's really the soaker pad that is adequate for absorption. Then the wool liner stops the stream well, and the wool cover is just for the wetness that comes on any other part of the diaper, and extra insurance.
Good luck!