MX - is tackling allowed?

[Wombat]

Earlier today I was watching the British MX Championship on the telly and I saw a rider bring another bike and rider down in a flying tackle.
 
It was during an angry duel for third place (Championship overall?) between James Noble and Brad Anderson.
In the final moto they collided and fell together three times in three laps; it appeared Anderson was the aggressor with really angry slams in the corners.
As they attempted to pick their bikes from the deck and resume for the third time, Anderson was first to mount his bike and attempted to ride off.
Noble left his bike on its side and dive-tackled Andersons bike and brought him down again!
They both retrieved their mounts and took off with one or two laps remaining.
As it came to a climax Anderson went into another corner alongside Noble - again too fast and angry ; Noble 'side stepped' and watched him fall...

We've all seen strange things at races and I'm wondering if anyone else has similar events they've witnessed or a been a part of ?

[TM BILL]

Seems a lot of fuss over who gets to be 2nd loser Perhaps if Noble put the same effort in earlier in the season he might have got as high as first Loser

[All Things 414]

Some guys should definatly be introduced to boxing. (more so some junior riders fathers.....)