Ricfly744 - AMS has actually got several deicing aprons located strategically throughout the airport. Subject to the operational requirements of crew they can get deiced right near the threshold of several runways.
The crew operating the equipment near the runway after deicing will give you the information over VHF and could facilitate this check. Realistically though, there is little to no logistical option to have someone visually inspect from outside, so the only option you have is to look out the window, an overwing one would be best placed.
JeroenC is right though, don't like it (the HOT), don't fly it. It's not worth becoming a statistic.