Good point about naval vessels. Some aircraft as well. In that area anything's possible. The electronic warfare ships or an EA6B Prowler can easily wipe out anything that's broadcasting for miles around. I've seen this happen on a practice range where we were we flying some stuff. Suddenly the controls on 4 planes went absolutely nuts from an E6B "playing music". On 1.3 and 2.4 gigs using hop tables no less!

If those two planes were on the same frequency then they were probably shot down from an outside source.