Stalls.....higher fuel load requires higher approach speed due to higher wing loading..crosswind issue ...if base turn put the wind at side of fuselage then wing on other side will see less air...wing seeing wind will have more lift than wing being blanked by fuselage exacerbating stall potential.Had aircraft been crabbed into wind with higher approach speed loss may not have occurred.this is why full size will dump fuel to attain landing weight to meet required speeds for landing.sorry bout your plane loss.