Do you think some Man u and barcelona games are fixed?

Like Man u last season were losing 2-0 twice against different teams (so lots of people bet that they will lose) then they won 4-2 against blackpool and 3-2 against the other team i cant remember. It isnt luck because it happens every season and they always get cheap penalties. And in the Barcelona game against arsenal Robin van persie got a second yellow card for kicking the ball 2 seconds after the whistle was blown in a stadium with 90000 people screaming. I guess we will never really know what is going on. what do you think?