NIK focus on the video mate. I reckon these two guys just found out one of their friends or brothers has been killed fighting te holy war, and rather than travel to the front line, they drive round til they spotted a soldier (in this case a guy with a help the heroes t-shirt near a barracks I believe) then ran him over and attacked him with a machete.
The guy is actually apologising that women and children had to witness that and says that in his land women have to witness this everyday in a deep London twang.
No sleeper cell here, no pre-planned terror, just mentalists going mental.
I could be massively wrong like.