Hi Richard
Not sure I follow that..... Are you saying in your example above that my employer would own copyright to any images I took even if I was not being paid at the time? ... Because they had provided the tickets to the race?
It could certainly affect me if the above is true
Does't make any difference if you are being paid or not. If you are formally an employee, and you take pictures which you would not have done without that employment, then you almost certainly don't own copyright.
Of course, it is hardly ever a problem so never gets put to the test. But I have been involved in a case where the employment link was about as tenuous as it gets, it went legal and the employee lost. A few thousand quality images over many years

There was a thread on here along similar lines a while ago that was settled out of court, in the employer's favour.
If you do this kind of work, and many of us do and there is never any clash of interests, you should get it formally agreed. If you're going to have difficulties, the crap usually hits the fan after you've left under a cloud! Often all it takes is for you to gently take the initiative and write something - very innocuous, along the lines of my pictures are mine - get it counter-signed by your manager/personnel/authority and dropped in your file. Don't kick up a fuss or you'll probably lose! The law is on the employer's side and you are asking for a concession.
You should take advice, privately. Sometimes it's better to do nothing or you might get whatever photographic priviledges you have withdrawn. These things can get very sensitive. Tread carefully. There's usually nothing written about it in contracts because it's the legal default.
O think the example is a bit more complex. IF you are are employed as a company photographer and IF you go to an event as part of your job then the images belong to your employer. IF for exame you are an accountant and go to an event on behalf of your employer and take photos then the images belong to you unless you've made an arrangement beforehand. That's how I've seen it work in practice.
That is indeed how it usually works in practise, because there is no clash of interests. But technically, when push comes to shove, the onus would be on you to prove that the images were of an entirely personal nature and completely unrelated to work, which when you're out on a work related event, is kind of difficult. The employer doesn't have to prove anything.
These things usually only become a problem if you leave to work for a rival, or start selling stuff, publish images of colleagues and they object etc.