With a stalwart like Saeed Ajmal reported, players are bound to more cautious of bending the rules.
The 21st century has witnessed a plethora of bowlers' action scrutinised.
Gayle brought up his fifty off 28 balls and shares his record with Ian Botham and Foffie Williams.
Shillingford hit a 25-ball fifty against New Zealand in the first Test.
Gibson called the batting performance "bitterly disappointing."
New Zealand wrapped up only their second-ever Test win on Caribbean soil in four days.
Shillingford missed the world record by just one ball.
Mark Craig was awarded the man of the match award on debut.
Jimmy Neesham became only the eighth player to score two hundreds in his first two Tests.
New Zealand lead West Indies by 489 runs and West Indies finish the day's play without losing wickets.