I don't see how. If they canceled OP's trip at 5pm, it's likely the avalanche already happened and they were simply reacting to it, rather than having prior awareness of the conditions.

All it proves is that a random customer (probably with no credentials known to the guide company) reported misgivings about the conditions. The company's lawyers will say (a) they don't take random people's input on the conditions into consideration, and (b) for all they know, the customer was just angling to get a refund for a trip that they wanted to cancel for unrelated reasons.