An Upasaka is a layperson and the vows do not say no sex only no sexual misconduct.

Upāsakas and upāsikās, also called śrāvakas and śrāvikās - are householders and other laypersons who take refuge in the Three Jewels (the Buddha, the teachings and the community) and practice the Five Precepts. In southeast Asian communities, lay disciples also give alms to monks on their daily rounds and observe weekly uposatha days. In Buddhist thought, the cultivation of ethical conduct and dāna or "almsgiving" will themselves refine consciousness to such a level that rebirth in one of the lower heavens is likely even if there is no further "Noble" Buddhist practice (connected with the Supramundane goal of Nibbana, "Unbinding"). This level of attainment is viewed as a proper aim for laypersons.[2]

In some traditional Buddhist societies, such as in Myanmar and Thailand, people transition between householder and monk and back to householder with regularity and celebration as in the practice of shinbyu among the Bamar people.[3] One of the evolving features of Buddhism in the West is the increasing dissolution of the traditional distinction between monastics and laity.

For all the diversity of Buddhist practices in the West, general trends in the recent transformations of Buddhist practice ... can be identified. These include an erosion of the distinction between professional and lay Buddhists; a decentralization of doctrinal authority; a diminished role for Buddhist monastics; an increasing spirit of egalitarianism; greater leadership roles for women; greater social activism; and, in many cases, an increasing emphasis on the psychological, as opposed to the purely religious, nature of practice.[4] https://en.wikipedia.org/wiki/Householder_(Buddhism)

Being a Buddhist is not a prerequisite for the 'path' outlined in TMI. The Buddha taught a merit based path for laypeople and a meditation based path for monks.

Culadasa was never a monk and before he moved to Arizona I don't even think he had been on a retreat. Technically he is not a neuroscientist as he has no degree in that field and did not do neuroscience specific research. Neurotheology is a thing but he did not publish in that field either.

The maps he talks about were based on meditation practices intended for monks. The West has already legitimized the trend of laypeople practicing the teachings intended for monks. This I believe has lead to much of the confusion between the way these practices are taught and interpreted between different western teachers....Daniel Ingram vs Culadas for example.

Outside of why he calls himself a neuroscientist I see nothing wrong with his teachings or his moral behavior within the way these things are interpreted and practiced in the west. It is like following a streamentry path and the jhanic maps of that practice without having developed a believe, understanding or acceptance of rebirth. Culadasa discussion of rebirth does not follow the traditional Buddhist view.

So from a pragmatic and secular prospective Culadasa's behavior did not break Upasaka vows as the circumstances do not technically represent sexual misconduct. Poor judgement maybe.