At the wrong time i imagine a split second of extra gas could be very nasty, hope you get it sorted bud.
Take the carb off and open the throttle fully and check if the needle is bent and catching the nozzle guide.
Gently check the needle is secure and cannot be lifted upwards into the carb slide, there is a retainer inside the slide that holds the needle and clip in position, if its not right the needle may be able to come up out of the nozzle tweak sideways and jam.
Carb slide jamming? Any dirt or damage. Seated on guides correctly?
Check cable route Start bike turn bars full left to right, any change in rpm? Check twist grip assy
Some 2t oils can emulsifiy in wet weather, only ever seen it happen on old 2t roadrace bikes with open carbs but maybe. White/yellow residue on carb slide
If it happens again clutch it and kill switch. Dont touch the twist grip as opening it again could relocate a rogue needle or stuck slide. take the carb off and have a look whats going on.