I've been cruising my way through
Essential Captain America volume 4 and I finally reached the climax of the
"Secret Empire" storyline. But boy -- did Cap #173 ever screw up! First, check out the cover:

Look at Cyclops there over on the left. First, why is he seemingly
lifting his visor up to fire his optic beams? Second, why is his beam
melting that SHIELD agent's gun?
Gil Kane -- I'm calling you OUT!! ;-)

But that's not the end of it. Inside the issue, we see Cyke do this:

Starting a forest fire -- by shooting his eye beams!! COME ON!! Looks like a few folks (um, Steve Englehart and Sal Buscema) forgot this little nugget from X-Men #43, a small special segment dealing with the X-Men's powers and origins:
This issue was from 1968, so there's no excuse for the creators of Cap #173, which was published in 1974, not to know this important info about the X-Men's field leader!