A bent con rod will either be caused by a siezed big end bearing due to lack of oil, in which case there is unlikely to be evidence under the head, or it could be because of a hydraulic lock because oil or water has entered the bores, can't really see how that much oil could get in though.

If the engine failure was caused by low oil levels, there could well be evident signs of wear in the valve gear, especially the camshaft bearings, cam lobes and followers / buckets. These parts are furthest from the oil pump, and will wear the fastest if the oil level drops so low that oil pressure cannot be maintained.

Things to look for are score marks on the cam bearing journals, wear or 'blueing' on the cam lobes through the case-hardening, and the same on the followers.

It's a little unusual to bend a conrod without either breaking a piston (hydraulic lock in the cylinder, dropped valve) or catastrophic big-end bearing failure.