Self employed or Employee?

[AngryVATman]

A sole trader chiropodist client is ill and has asked another professional to tend to his patients for 6 months. Under the agreement, the individual will spend a couple of days a week at my client's place of work and remit 50% of total takings to my client to cover overheads (rent, supplies etc).

Does this sound on the face of it like and employment or self-employed arrangement?