I just had my own "interesting experience" with buried electric today. Home owner's 60 amp feed from house to garage. Obviously not checked when I called DigSafeNY. We hand dug down where the conduit enters the garage and saw it was over 18" deep. But, low and behold, my 4 foot rototiller hits the line barely 20 feet from the garage. The yard is quite level but here it was maybe 6'' from surface. Stalled the tractor with plastic conduit wrapped inside the tiller, popper the 60 amp branch breaker AND the 100 amp main breaker in the house. We weren't sure quite what had happened and so called the power company who came right out and verified their stuff was OK coming into the meter and box. The service entrance was clearly overhead wire anyway.
Luckily the homeowner (very good friend) was relieved that I wasn't hurt or killed and was less concerned with the damage. We sat down and had dinner while discussing next steps. I need more seat time on the backhoe anyway so will be heading out this weekend to dig up the damaged line and dig deeper to get ready for the replacement. Seems like buried electric lines attract one or many of Murphy's laws