The definition of both state and phase depend highly on the context of the discussion. Knowing the context of the discussion is the responsibility of anyone involved in the discussion.
State generally refers to a condition which the matter is exposed. When exposed to certain conditions matter may take on a particular form, which the form is sometimes referred to as a state depending on the context of the discussion.
Phase when discussing chemistry generally refers to portions of matter which are physically distinctive. Phase may also refer to a state within a cycle depending on the context of the discussion.
Phase and state can be completely synonymous, again, depending on the context of the discussion.
Example:
A chemist working on a batch reactor may refer to the state as the condition of the reactor and refer to the phase of the matter in the reactor.
Another chemist working on a similar batch reactor may refer to the phase of a given sequence in the reactor's operation and refer to the state of the matter in the reactor.
Yet another chemist with a similar batch reactor may interchangeably refer to the 'state' or 'phase' of matter in the reactor.
Alone, both 'state' and 'phase' can be ambiguous; however, this ambiguity can be avoided through clear communication of the context of the discussion.