The goal - from watching the highlights - was actually headed from a central position rather than at the back post. I thought it was another back-post header at the time. Although it was Gunter (now the left back) marking him, so it's a fairly pointless quibble. We did let crosses in far too easily from Reading's left, and generally a header the left-back should be challenging for was allowed to happen.
In my view it's a symptom of the way we play going forward.
We don't have orthodox wingers - Ando was on the left, so was generally cutting in, Cohen on the right just isn't a winger.
This means our fullbacks tend to push on to give us width - both Gunts and Shorey love getting forward, but that can leave us exposed. Gunter has pace to get back, I'm not sure Shorey does. At least two of those crosses from our right could have been pressured sooner by either Gunts or Cohen, possibly all three - so there's the first problem, letting the crosses in.
At the back stick at least once Shorey was caught out of position when presumably breaking. These things do happen, but they can't happen three times in one half like that.