Battlefield 4 Server Rules These rules apply to all of our BF4 servers as of April 2020. There are significant changes from our rules in the past in that there are far fewer rules, and for the most part it's everything goes outside of what's listed here. Our admins operate on a point system...
banzore.com
As long as they did not attack uncap in order to steal the heli, the situation that you described is within our rules.
If the enemy team steals a vehicle and denies your team from reclaiming it the entire game, that is also fine.
Please also note that we typically require video evidence for complaints as we value the additional context such video provides.