Mrs. Rusholme occupied the firm of Saunders and Watts to refinish floors in assured rooms of a home owned by her and her husband in Red Deer, Alberta. She told Mr. Saunders that she and her husband would be away on vacation and that she would leave a key for the workers with her next door neighbor. She asked Saunders to leave the windows partially open for ventilation and to give the key back to her neighbour who would close the windows when the floors were dry. The Rusholmes' house was serviced by gas. Between the appliances was a gas stove in the kitchen with a pilot light (a small flame within which will ignite the burners or oven when the burners or oven are turned on) which could be turned off by hand. The downstairs floors of the house, including that of the dining room, were to be sanded; the dining room was next to the kitchen with no door among the 2 rooms. After sanding the floors, Saunders and Watts applied a sealer that they had bought from Standard Household Products Ltd. The label on each can of sealer contained the following warning:

DANGER-FLAMMABLE
Do not smoke. Adequate ventilation to the outside must be given. All spark-producing devices and open flames (furnaces, all pilot lights, spark producing switches, etc) must be eliminated in or near working areas. Avoid prolonged breathing of vapours. Wear a vapour cartridge mask. Replace cartridge before saturation.
About 8 hours after Saunders and Watts left, an explosion happened in the house and it was seriously damaged. On returning home from their vacation the Rusholmes found their home in ruins, and were dismayed to discover that they had neglected to renew the fire insurance policy,which had expired only a few days before they had left on vacation.
The Rusholmes brought an action for damages against the firm of Saunders & Watts and against Standard Household Products Ltd.

Outline the legal questions raised by these facts and provide your opinion of the probable outcome of the court case with reasons.