This is a widely (and often HOTLY) debated topic. Just like in a restaurant, tipping is up to each individual and the experience they have. As a former guide, my rates were based on cost of fuel, bait, insurance, equipment and my time. I guided only on my days off my regular job and used it as a way to fish more bodies of water and meet new people. I guided people that had unrealistic expectations and those who basically paid me to take them for a boat ride and show them the lake. One guy literally sat in my boat and read his book and insisted that I fish, as he wanted to just enjoy the day and see different species of fish caught, while others told me at the end of the day that they were disappointed that they weren't taking home their 3-man limit of panfish in a half day trip (father and his 5 and 7 year old kids). They took home 40-some crappies and gills (I never wet a line, so they did the catching, not me) and literally spent 4 hours untangling lines and re-spooling reels. I said all that to say this...there are MANY variables present that even a seasoned guide has no control over...weather, client fishing ability (or lack thereof), etc. I always focused on the things that WERE within my control...being polite and helpful, boat control, making sure equipment was maintained and I had plenty of bait, etc. I had a client hook me in the forearm 30 minutes into a trip once. He insisted we go back to the launch and leave to have it removed. After a few minutes it didn't hurt all that much and I told him I was fine with cutting the hook off the lure and leaving it so he could continue fishing. He tipped me $100 and told me nothing he could give me would ever be able to repay me for toughing it out for 3.5 hours after having a treble hook buried in my arm. We ended up catching quite a few fish, including his biggest smallmouth.
In your specific case, that 'guide' was WAY out of line yelling at your dad for almost falling on his rods (he could have just as easily fell out of the boat and hurt himself) and I would NEVER pull clients off fish if they were catching them and having fun unless they requested it or were wanting to try multiple spots and I knew I would be able to get them back on fish. The reason I stopped guiding was because the wear and tear on my equipment and boat was not worth the part-time money and people being inconsiderate and flat-out rude. I always told my clients that I would demonstrate the technique and show them how to fish the pattern we were going to fish and then let them try to mimic that while I helped them. Some would insist I fish with them, but I never tried to 'show up' my clients. If I felt I was catching substantially more fish than them, I would just set my rod down for a while and try to help them put more fish in the boat. As a guide, you should set your rates such that you don't need to be tipped to make it. A tip was always a nice surprise, but there was also a few times that I refused to take it. It should not be expected.
My favorite guide trip was not even a scheduled one. I had a client no-show me one morning and after launching my boat and waiting at the landing for nearly 45 minutes, I had made small talk with a Vietnam Vet named 'Nick' (to this day, I still do not know his last name, never asked) he was catching a bunch of small gills off the dock at the launch, and mentioned that his wife said if he could catch them some bluegills she would clean them and make fried fish and potatoes for supper. After chatting with him for a while, I gave up on my clients showing up and asked Nick if he wanted to join me for a while on the lake. The smile on his face didn't require a verbal answer. I helped him into my boat and off we went. Over the next 3 hours, he talked about his life, the war, his family and losing his best friend and fishing partner the previous year. We caught some dandy gills and he took 8 or 10 home for dinner. When we got back to the launch, he wanted to pay me for taking him out. I pointed to his Vietnam Vet hat and said he already had, and thanked him for the company and 'showing me how it was done'...I helped him carry his small cooler of fish and fishing gear to his car and off he went. Initially, I was peeved that those clients stood me up...but by the time I loaded up my boat, I was kind of glad they did.
If you feel the experience was better than you anticipated and feel the guide went above and beyond to get you on fish and you want to tip him/her, then feel free. I never once was offended by someone not tipping me. I didn't expect it and it was always a nice surprise if they did.