they just said we need to terminate your contract as you breached company policy 
what part of it? you didnt steal anything. they cant expect you to grass up anyone for stealing. id get legal advice, wrongful dismission.
theyll just say its gross miss conduct probably.he should of reported it, he didnt, end
good luck finding a new job bud
but no proof really, just as he was there doesnt mean he knew whay was going on.
saying that, most companies wouldnt be daft enough to sack someone if they thought they had nothing to back it up