I would be grateful for your thoughts on the following. I have a 2004 Corolla Verso. It had a main dealer service and oil change at 90,000 miles 7 weeks ago and 2,000 miles ago. Today, after driving locally 40 miles and stopping several times, it failed to start with simply a clicking noise. On lifting the bonnet I discovered the dipstick projecting approx 6 cm out of its normal position. Replacing it correctly enabled the car to start on the second try. Back home I checked the oil level once it had cooled to find it well down and some sludge on the tip of the dipstick. 2 litres of oil has brought the level on the dipstick back to recommended level. There is still a hint of sludge. At no time did the oil warning light come on. Is there an explanation for this occurrence other than human error? And should I arrange for an oil change to attempt to minimize further engine damage?