Since the Omnitrix contains DNA samples, it's not explained how, in the Omnitrix explosion, four of the samples turned into fully-formed aliens.
Ben, in this two-part story, has become completely calloused against feeling for others. His big concerns center about seeing a Sumo Slammers movie and drinking a smoothie. Of little to no concern, Kevin and Gwen's near defeat from Ssserpent (in Part One) and Kevin's possibly permanent disfigurement from the Omnitrix explosion.
In the past, spidermonkeys are shown to be intelligent life forms, yet when Ben confronts his spidermonkey from the Omnitrix, it is a mere beast.