At the end of the reaction you washed the chemicals into a beaker using water. Why was it OK to use water to do this if Grignard reagents are very reactive towards water?

water could be used to wash it since the reaction has ended.

Explanation:

There will be no reaction of water with the Grignard reagent since the reaction has ended, as it is well known that water is a universal solvent for washing of glasswares after experiments but if it is during the reaction it will be more advisable to rinse with alcohol to enhance more accuracy during the experiment