Records. Records. Records. You cannot have enough. And, surprisingly, it doesn't take that much extra time to keep thorough records. Ask the contractors who do keep copious records. They will tell you it's worth it in the long run.
Along with records, depositions are utilized to determine what happened from the viewpoint of the parties involved. Depositions are not designed to "trip you up" or catch you being untruthful. However, often deponents try to skirt the truth in an effort to get themselves off the hook.
Big mistake. Not being truthful in a deposition creates some huge issues for all concerned. However, more often than skirting the truth, deponents will "guess" at answers instead of simply stating "I don't know." Deponents should answer each question truthfully and to the best of their knowledge. Don't guess and don't assume.
Likewise, only answer the question on the table. Contractors can get themselves into trouble by "explaining" to get the lawyers to "understand" your position. Don't do that. Lawyers will ask questions to find out what they want to know. They can ask follow-up questions if necessary. If the plaintiff’s lawyer doesn't bring out the points you want him to get, then your lawyer will do so. And, if your lawyer doesn't get it out then, he will do so at trial. Trust your lawyer (or the insurance company's lawyer). You know the snow business. They know the legal system.