The Jaguar driver lost control in the braking zone to the 90-degree left of Turn 7 on the second lap of Sunday’s race, having locked the rear axle when running behind championship rivals Jake Dennis and Cassidy.
Evans hit the Envision Racing machine of Cassidy directly ahead, being launched into the air before landing in the barrier while Cassidy took to the escape road.
Both drivers rejoined at the back of the field, with Evans pitting for a new front wing before retiring three laps later due to suspension damage.
“They slowed up a lot more than I was expecting, and I reacted to it but then I locked the rears and once I locked the rears I just went into Nick,” said Evans, who had won Saturday’s Rome E-Prix.
“When I rode the wheel, it just exaggerated everything, it escalated the situation.
“Very minor thing and then, it just shot me over the top of him and took me out of the race, pretty much took him out of the race as well. Just a really shit situation.
“Obviously I’ve got to take it on the chin, and I’ve got to put my hands up but it’s not like I was doing anything weird or trying to do anything dirty. I’ve barely touched a car the whole year.
“I just feel bad for taking me out of the race for my team as well. Probably more so for Nick because he did nothing wrong and with Jake winning it’s really damaged his chances.”
Cassidy entered the race two points ahead of Dennis in the standings and managed to finish 14th having struggled to make ground in the pack and was handed a five-second penalty for a last-lap collision with Dennis’ Andretti Autosport team-mate Andre Lotterer.
Dennis went on to win the race having led every lap from pole, and now leads Cassidy by 24 points with only the London E-Prix double-header remaining.
“He did most of the talking,” said Cassidy when asked about Evans speaking to him after the race.
“He’s a great guy, he’s a great driver. These things happen but it’s still heartbreaking.
“My roll-hoop was taken off and the halo was damaged, I’m quite lucky. Obviously, that wasn’t my first reaction but looking at the car now very lucky.
"I don’t really know [if the performance of the car suffered], it would be wrong for me to say yes there was without knowing.
“I was actually still really fast in the race but couldn’t do anything.”