You know what's funny -- and you can look in my profile about this -- on geological timescales, CO2 volcanic emissions are a significant climate driver. Tectonism actually has a variable rate -- and if it speeds up or slows down, this affects uplift, erosion, sea level, shallow water carbonate deposition, and subduction of carbonate sediments into the magmatic upwelling zone (i.e., "Ring of Fire" currently). All of these factors affected atmospheric CO2 concentrations through paleoclimate history.
But now that man's involved, we're pumping it into the atmosphere a lot faster than volcanoes ever did, with the possible exception of flood basalt emplacements like the Deccan or Siberian.
...CO2 volcanic emissions are a significant climate driver... Wait a minute, tectonism may be having a lot more effects then raising CO2. Why do you assume it wasn't some other aspect of such events?
But if your right, shouldn't we see CO2 go up either before or at the same time as the temperature when such an event is to blame? Put another way: what is poking the bowling ball in this case?