the red devil

Took my new-to-me 2001 SV650N for an oil and filter change at a local garage this morning, picked it up an hour later, and rode about 1–2 miles, uphill, overtaking a line of traffic as I went. Revved to maybe 7500 rpm. Stopped at some lights and realized my right shin was covered in oil, the oil filler hole was smoking, and there was no oil filler cap on the hole.

The mechanic came and picked me up in a van, took me back to the garage, and topped up the oil. About .25L had gone missing – the sight glass showed the oil level hadn't dropped below the minimum mark. New oil filler cap was added (apparently from another SV 650 they had there as a project bike).

The mechanic tells me it definitely won't have done any harm to the engine. He seems a nice enough bloke, but he does have an interest in thinking that. Anyone else had a similar experience to this, or knowledge of whether the engine will have been affected?

Thanks!