I would be VERY careful about ascribing motives to people without talking to them. As long as a judge takes enough of a bite of something to render a reasoned score, I couldn't care less what they do with the remainder.
What constitutes a reasonable sample to some may be smaller than what it is for others and how much meat someone can consume in a two hour time period may differ as well.
IMHO weeding out a bad judge is a much better solution that disallowing the use of coolers or ziplocks.
If, as a competitor, you are concerned about judges not trying enough of a meat to render an informed opinion, ask the organizer to have the table captains alert the rep when they see scores that are out of whack that coincide with judges who take small bites.
If those judges have to be warned/instructed more than once, ban them.
2 Thessalonians 2:15