idgas ain't wrong - our company went through a lot of pain on this subject and along with the usual "it's all the Bond" stuff there are some important points to consider.
1. By analysing a bar post flight, it is
usually possible, to determine whether a bar is short by cash or by stock or by both. Stock issues may be pointed at the Bond, but it is difficult to exclude Crew from the loop on cash.
2. There are (broadly) 2 areas in a bonded store: The stock/warehouse area where stock is stored, and the area where bars are packed. For accounting purposes, the stock is counted out of the first into the second, so that the airline can be billed for the stock. If you're in a Bond and a robdog, why nick from the packing area, where discrepancies may be noticed by your employer, the crew, or other packers, when you can nick from the warehouse stock, which may not be missed until the next stocktake, possibly in a week or two's time?
3. Some crew nick stock, or money. Only a very, very, very tiny percentage, but it does happen. We know because they invariably get caught in the end, since our employers aren't quite as stupid as they like to pretend. When they finally get caught, it is always a surprise: You can't believe that the person you have sat with on the jumpseat so many times, and shared your highs and lows with has been stealing from the company (and you, of course if you are paying bar downs) but they have. It happens.
4. Some crew nick stuff without realising it. The toilet roll that you took home in your crew bag because you had run out and needed some before tomorrows's visit to the market. The miniature each that was taken from the comp bar after a really bad day: The tonic that you took home because you had run out and needed something to mix with the gin when you got home that night: The cup of coffee that you bought from the machine in the office using your bar float. All minor stuff, but if you get caught and your employer is having a bad day, you may have difficulty explaining it away.
Please don't think that I'm condoning the practise of recovering bar shorts from crew - I'm not. My employer now has a practise of only applying bar shorts to crew in thiose cases where there is a substantial short, and
procedures and paperwork have not been adhered to correctly. I believe this to be fair, and have not paid a bar short since the provedure was introduced over a year ago.
If your employer does take bar shorts out of your salary (as previously mentioned, this has a highly debatable legal standing) then there is one question that is important to ask, namely is the short based on the retail price or the stock price. If your bar is short by 10 whisky miniatures, sold on board @ £2 each, so a total of £20, but the company in fact only bought the miniatures from the Bond/wharehouse at £1 each, then by applying the bar short to the crew at the full retail price of £20 means that they are in fact making a profit on the actual bar short, from the crew. Food for thought?