I just had an interesting encounter with some spartans, to put it mildly. I had shot down a small ship, and the battlescape was one with all the plane wreckages. My guys start spreading out, killing a couple of the enemies, then i use a heavy cannon with explosive munitions on one of the spartans. Then all hell breaks loose, explosions start happening all over the place. I didn't see any explosive barrels or anything, so i thought maybe there were some weapon crates in the explosion...but the explosions continue for about 30 seconds nonstop like a wildfire, spreading far beyond my fog of war. After what felt like 10 minutes of explosions, i hear maybe 6 or more death sounds and the mission is complete, without me even having spotted their ship. Not even in the refinery battlescape were the chain reactions this excessive, so i'm wondering if it's a bug?