I would suggest working together with your buddies who accompany you to the contest. Before each attempt, one of you would check to make sure the bar is loaded symmetrically on each side. Sometimes one loader will not load the bar correctly and the bar will be heavy or light on his side. This can prove to be dangerous to the lifter as well as the spotters as this greatly increases a chance of the lifter missing the lift due to loss of balance. Also, make sure the collars are put on securely and the plates are tight together from the inside collar to the outside collar.
Loose plates can also compromise control during execution of the lift.
Another good check is to make sure the platform is dry and uncluttered. Spotters may get lazy and not put the loose plates back on the rack which can create a serious tripping hazard. Another hazard is excessive chalk dust on the platform. Have the spotters wipe the dust up occasionally. As the squats proceed, I have seen the racks edge farther and farther forward until they are almost tipping over the platform.