Conservative newcomer Iván Duque wins Colombia's presidential election the BBC News use an odd phrase

This BBC report https://www.bbc.co.uk/news/world-latin-america-44513368 on the Colombian Presidential Election result contains this oddly worded sentence:

'He also says he will impose tougher punishments on crimes allegedly committed by the rebels during the brutal five-decade conflict with the government.'

On crimes? Surely that should be for crimes. Also surely the punishments won't be for crimes allegedly committed by the rebels but for actual crimes, unless the BBC believe that the rebels are freedom fighters thus with clean hands.