I had the same experience in Red Hordes. My flamethrower team hit twice with a full load from perhaps 15 metres. The grass around the T-34/85 burned for quite some time, but that was all. During the impact of the burning oil it seemed like the whole tank was getting up in flames, but it appeared again, completly untouched, like a Phoenix from the ashes. Pity. Would have been such a nice memory.
Btw, very nice scenario.