Quote from wayneL:
You might want to recheck your assumptions there.
Higher gamma in a call gets you fewer deltas as the underlying moves down. In other words it gets you less long, ergo, less loss. (notwithstanding other Greeks)
Maybe you can check your assumptions again. A higher gamma means that the delta of the short term call goes to zero quicker than the delta of the long term call. And as we all know the lower the delta the less an option is worth. So in this case the short term option loses a lot more percentage wise if the market goes down than the longer term option.