I know this thread is nearly a year old now, but there's no time limit on safety.
It's a fact that accidents always happen when you're not expecting them.
Reminds me of a friend of mine several years back, he was clearing a right of way with an 026, he wore his chaps all day even during his lunch break, then at the end of the day he pulled them off, was about to put his gear away when he looked back at where he had quite working, and noticed one small limb he had missed up on the side of a small embankment, it wasn't more than 1 & 1/2" in diameter, so he decided to fire his saw up and "just knock it down real quick" didn't bother putting his chaps back on for such a small thing, stepped up on the bank, cut the twig, went to step back off the bank, fell and got raked across the side of his hip when he fell on top of the saw.
The cut was about 1/2" wide x 5 or 6" long x about 5/8" deep.
Believe it or not, he was lucky, the chain was dull, so he had work a little harder cutting through the limb, the chain got hot, which cauterized the wound.
It looked like someone cut a ham with a chainsaw. It never bled a drop.
They cleaned it up with alcohol pads from a first aid kit(I thought it was a bad idea being as how clean it looked anyways) , and took him to the hospital. He was months getting over that one, because it kept getting infected. He still has nerve damage from it.
Most accidents that I've seen were similar. Usually in the last 30 minutes of the day. Guys get over confident, are ready to go home, and they drop their guard for a minute, and something happens that wouldn't have if they'd taken the extra minute to do it the safe way.