The pinout diagram in datasheet has Drain and Source pins swapped compared to:
1) what seems to be a standard pinout of these parts
2) what's shown just few pages later in the same datasheet - the two layouts on top of page four.
I'm attaching screenshots of both diagrams. At least one of them has to be incorrect.
The version of pinout with 4 of the pins + the big thermal pad connected to source, that version is mentioned in the datasheet twice, which would be a reason to trust that information, if there wasn't also a reason against it - I looked into over 50 datasheets of p-chan mosfets SON-6/DFN-6 packages today, and 100% of them had that part connected to drain, like what indicates the other diagram. That pinout seems to be a standard for single p-chan mosfets in 6-pin packages, and a surprisingly well respected one. I couldn't find a single exception, except for this TI part, and even this part isn't consistent about it in its datasheet.