"Article 2: Striped Players
Players within the specified weight ranges of one or two stripes will have their
helmets marked accordingly:
• One Striper - A neon green stripe placed vertically at the center rear base
of the helmet.
• Two Striper - A neon green “x” placed at the center rear base of the helmet.
Neon stripes are available from the INFC office and your club.
All Weigh-ins will adhere to the INFC weigh in procedure. Players exceeding
the maximum weight in the 3rd, 4th and 5th grades prior to the start of each
game will not be allowed to play. Illegal participation by a player will result
in a fifteen-yard penalty. The Commissioner will impose further penalties to
the coach and/ or team if it is determined that the player/players were used
illegally in order to change the outcome of the game. Weight limits are set by
INFC for safety and must be strictly adhered. No exceptions will be allowed
or tolerated.
A. One Striper:
Offense
1. May play end but is not an eligible receiver and cannot advance the
ball in a designed play but may advance the ball after the recovery
of a DEFENSIVELY CAUSED fumble.
2. Not allowed to line up in the backfield except to place kick, for extra
points or field goals. Must be a declared kick, a fumble or fake will
be declared a dead ball. If the kick is blocked and remains behind
the line of scrimmage, a One Striper may advance the ball.
3. May place kick but cannot punt.
Defense
1. May play any position.
2. Not eligible to return a kick off or punt.
3. Allowed to return an interception or fumble."
Straight from the rule book. I made bold the pertinent part near the bottom. You are correct, that shouldn't have been allowed, at least per the rule book.