I always primary in a 7.5 gallon bucket with an airlock. Once or twice, some krausen snuck out through the top, so I just pulled if off, rinsed and sanitized and stuck it back on. Once, I needed a blowoff tube (for Cheesefood's caramel cream ale recipe). No problems, so far!
As far as that timeline, I'm not going into an argument about how long it takes me. I will tell you, though, that I keep sanitizer in a spray bottle and a gallon jug mixed up, under my sink.
I can grab a saucepan and put a pint or two of water in it and get a rolling boil in under 3 minutes, pull it off the stove, add the DME and bring it to a boil again in about another minute. Let it boil while I grab the growler and foil. Squirt the foil, dump some sanitizer in the growler and shake it up. Turn off the stove, let it cool or put it in the sink in a bigger pan with some cold water in it. Dump the sanitizer out of the growler, pour the starter wort into the growler, pitch the yeast and put the pan in the dishwasher.
Definitely less than 15 minutes, probably less than 10. However, I'm not trying to convince you that my way is the "right" way. Right for me, definitely- maybe not for you. But if it took me more than 15 minutes to make a starter, I wouldn't do it!