Meter tails going into top of CU

[tim-spam]

Just noticed the new CU in my parents' house, and the meter tails go in at the top straight into the 100A breaker. Is this OK, as the tails could be pulled straight out of the top, although I guess if the terminals are correctly tightened, this would not happen?
The reason I ask is that the CU in my present house (and all the previous ones as far as I can remember) has the tails entering at the bottom, going behind the rail and looping over to feed into the main breaker terminals. This would provide some protection against loose connections allowing the tails to be pulled out.

 

[JohnD]

If you've got loose connections enabling the wires to be pulled out, I think the direction of entry is the least of your problems.

16mm tails are quite difficult to bend tightly, 25mm even more difficult.

 

[Qedelec]

More importantly you should ensure the IP rating of the top suface of the enclosure is maintained, This is IP4X which means that nothing larger than 1mm can be inserted.
The best way to acheive this is by filling the void with sealant around all the cables.