i was a witness for the defence, trouble is i was also a rookie copper when the case got to court. i made one slip up on my evidence and i got crucified. i was only in there for 5 mins but at the court for a day an half.
At the end of the day my statement etc is 100% accurate and honest so I have no problems sleeping at night - but my biggest worry is being ripped apart by the defence 
They will

the main thing is to have your facts, perhaps supported by written / noted evidence from the time, the more you can refer to notes the better.
Last in Court (Crown) about a month ago for 3 days, spent one and a half hours on the stand in one go

I expect to be in Crown Court next week, 4 days, so not know how many times, if any, I will be on the stand, I wrote all the reports, so Know my stuff.
Main thing is to be respectful to the Judge and It will not be as bad as you are worrying about.
