I think thats quite true. Ive used both online and direct with my broker on occasions it hasnt made much difference. Though i have to say for bigger trades i call my broker and try and do a deal with the market maker. That seems to be what your friend did yesterday with the 50,000 buy at under the offer. My best deals have been getting the broker to do a deal with the marketmaker. They dont like being messed about with small tranches though.
There have been times as well when they have demanded a premium and then the sp dropped later. There is no hard and fast rule.