He's made an awful lot of howlers this year as well don't forget, namely against Liverpool, Burnley, Spurs etc
You say "etc", when I think you actually meant "."
Because let's face it, you stopped because there were no others.
So what you have is in effect, the Liverpool game, (and I'm assuming you mean the Anfield Derby, because Joel was not to blame for the Goodison goal).
For me, he reacted awkwardly to the 1st. It looked strange. That's about it. If that was Pickford, people would be excusing him because our team, notably Gueye, just allowed Mane to waltz through the midfield and defence unchallenged. Noone was saving the second, and the 3rd was no worse than Lyons 1st goal in the away game, but again, it's worse because it's Joel. Reality is, we didn't lose that game because of Joel, but people blamed him anyway.
Burnley, he gave away a clumsy pen. No goalkeeper has ever done that... Thankfully, we won that game 3-1... and beat Watford 3-2.
And the spurs game. Joel passes to Schneiderlin who was asking for the ball, Schneiderlin loses possession and Joel gets blamed for the goal.
So really, yeah, that is the awful lot of howlers he made. He didn't dive, he gave away a pen, and he completed a pass to someone who lost it because he was, ironically, too afraid/wise to pass it backwards to Ashley Williams.
And let's ignore all the cleansheets, because that was down to the defence...
Ahem...