If you can reach rep 4 on a push press set, you can reach rep 5.....it was either a leg drive thing, or a concentration thing or a being winded thing......or your fanny pack was too tight and you lost blood-flow to the brain.....but for real.....if you miss a rep on PP's...just rest the bar across your delts and take a few deep breaths and try to hit it again, more often than not you hit the rep and the rest of the workout feels much better.
As for the front squats.....right now, just think of it as 'shit happens'...if it happens next time, worry about it and evaluate, but give it another go before getting concerned.
Also, 105 on skulls is some nice skull crushin'.