There is at least one differing account by another alleged witness (an officer in the Mexican army). According to that account the battle was actually quite short once the full assault began, there were at least a few survivors (including Crocket), and those survivors were put to death by torture.
“There is at least one differing account by another alleged witness (an officer in the Mexican army).”
There are, I think, 5 different accounts of Texan soldiers executed after the battle. These were written in later years in an attempt to throw Santa Ana in a very bad light.
This is one of the accounts that is trusted due to the source and his participation in the clean up of the dead.
That officer was LtCol. Jose Enrique de la Pena. His diary and other documents were printed in English in 1955. The de la Pena diary and papers are at the U of T in Austin. Needless to say, there has been considerable arguments about the authenticity of the de la Pena material. An American officer after San Jacinto, was told a similar story by one of the captured Mexican officers. Do not know the source of that story, read it many years ago. Certainly, if any of the fighting men had been captured alive, Santa Ana would have had them executed. That was his style.