How to verify end cut sealant applied to treated wood cuts

[Pat Murphy]

I just had a deck built, and ponied up for premium decking and railing. The contractor slopped a few things, including putting Vycor tape between the beams and joists. A few experienced builder friends commented that it appeared no end cut treatment had been applied to any of the exposed cuts on the treated wood (beams, joists, stringers, etc), though the contractor insists some was applied. Is there any way to verify whether or not sealant was applied to the cuts?