Well the bolt on mine has been reverted (not by me). I didn't even realise until Tony pointed it out during my geo. It had been fitted about 14 months beforehand. It's now been like this for 19 months and I've had no problems. Lower arm is a pattern part as well and I'm surprised it's lasted this long anyway!
There seems to be a lot of dispute about this on the MEG forum and some people think it's fine like this, whereas others will put the bolt in the correct way. As Tony says the price puts people off! I'm sure the lower arm bolts are reverted on some makes of cars out of the factory though?
However, you could argue about the subframe bolts as these are put in upside down. I had a scary moment last year when my subframe became loose on the M25 while doing 70mph, I could feel I was losing control of the steering as the frame was moving If I'd crashed that could've been nasty! One bolt had come undone and then seized in the nut, plus the other bolts were only hand tight and not torqued up. I suspect this could be down to a clutch change by the previous owner!
When me lower arm does need changing I will be making sure the bolt is put in correctly, especially as I have the little one in the car. I think I will be calling on Tony to advise me on this as lowering my subframe will be a pain cos of the problem I had. There is no longer a captive nut there as the bolt sheared when trying to remove it, so the nut and rest of the bolt had to come out from the floor. If the subframe is dropped and I have a new captive nut put/welded on, do you think this will will cost much more? I would obviously prep the area first.
Sorry for the long post!