I'd say van der Poel actually wanted it too much. That was his problem. Colbrelli meanwhile just seemed content to sit behind him & would have been indifferent had he lost. I'm not exaggerating here either, i.e. there's a reason some riders sit behind others & let them work: it's not always because they're outsmarting them, no, it's a literal game of bluff with some truth involved in the form of "you want it more, so work for it".Colbrelli won the race through being the smartest. Van der poel lacks racing intelligence. Colbrelli attacked at least twice and won the sprint.
Van derpol worked too much in the final 30km but all day colbrelli was taking his pulls and doing his work in the groups he was in. Just watch the footage.
If van der Poel hadn't pulled, they probably would have been caught by van Aert's group (& maybe Colbrelli also fancied his own chances in that scenario as well).