Was refusal to work insubordination or a legitimate concern?

Quarry operator ordered to pay the wages of two workers it suspended for three days after they refused to work
|Canadian Employment Law Today

Dufferin Aggregates v. C.E.P., Local 266, 2005 CarswellOnt 1272 (Ont. L.R.B.)

The Ontario Labour Relations Board has ordered a quarry operator to pay the wages of two workers it suspended for three days after they refused to work.

Trever Simpson and Clayton Fournier are experienced load operators for Dufferin Aggregates, a rock crushing operation. They dig, lift and convey blasted rock to the crusher at the processing plant at the quarry, using heavy machinery as necessary. The work is physically demanding.