No doubt if one of them died from being run over by a wagon, BroJoeK would regard that as the fault of the confederates too.
But to make it clear, none of those soldiers were killed in an engagement with the enemy. They were killed in an unfortunate accident.
BroJoeK really is stretching to try to include those two deaths as part of the battle. Other than that his commentary has been pretty reasonable.
Most accounts of the battle will tell you that the sole battle casualty was the Union horse.
These other deaths were the result of an accident while firing a salute.