Not exactly a tactic, but the blank stares into the shiny new rifle they dont know how to pickup is definitly a hilarious sight. On one map, a ROplayer was stopped looking at a rifle on the floor, in the middle of the doorway, which blocked everyone else from getting through. People yelled at him, and eventually another ROplayer shot him. It was the start of a brutal yet hilarious chain reaction as the 2nd ROplayer was shot, and then he was shot, followed by the person who shot him. Myself and the survivors were looking at the aftermath when a german MG'er apparently had time to go prone right in front of us and mowed us all down. I wish I had gotten a pic when it was all over, I could not stop laughing.
The 2nd thing I saw I only caught a few times. It was the dreaded first uses of satchel charges, I witnessed some dude charge a tank with a satchel, and when he was a good 20 feet from it he went from a running heroic soldier into a big vapor cloud as his charge detonated in his hands, taking out the poor soldier who happend to be near him as well. Other funny satchel sights I saw included people throwing satchels at moving tanks, without priming them, and when the pack finally explodes 10 seconds later the tank is long gone but your teamates are usually right there to take the brunt of the blast.
Good times, good times...