Consider: what's clearer?

    return &m_data[colInfo->offset + TUPLE_HEADER_SIZE];

or (since the tuple header byte comes first in the m_data buffer)

    return &m_data[TUPLE_HEADER_SIZE + colInfo->offset];

or (because array indexing == pointer math AND smaller code is better code?)

    return m_data + TUPLE_HEADER_SIZE + colInfo->offset;

I understand that this is partly a matter of personal preference. Do you find &x[y] more understandable, more abstract, higher level programming?
Do you find x + y to be more tricky/hacky? Or is x + y just simpler, making it easier. Which form lets you (personally) think LESS to understand it?